diff --git a/_fixtures/fncall.go b/_fixtures/fncall.go
index c837f919..4c39d276 100644
--- a/_fixtures/fncall.go
+++ b/_fixtures/fncall.go
@@ -76,6 +76,21 @@ func escapeArg(pa2 *a2struct) {
 	globalPA2 = pa2
 }
 
+func square(x int) int {
+	return x * x
+}
+
+func intcallpanic(a int) int {
+	if a == 0 {
+		panic("panic requested")
+	}
+	return a
+}
+
+func onetwothree(n int) []int {
+	return []int{n + 1, n + 2, n + 3}
+}
+
 func main() {
 	one, two := 1, 2
 	intslice := []int{1, 2, 3}
@@ -98,5 +113,5 @@ func main() {
 	runtime.Breakpoint()
 	call1(one, two)
 	fn2clos(2)
-	fmt.Println(one, two, zero, callpanic, callstacktrace, stringsJoin, intslice, stringslice, comma, a.VRcvr, a.PRcvr, pa, vable_a, vable_pa, pable_pa, fn2clos, fn2glob, fn2valmeth, fn2ptrmeth, fn2nil, ga, escapeArg, a2)
+	fmt.Println(one, two, zero, callpanic, callstacktrace, stringsJoin, intslice, stringslice, comma, a.VRcvr, a.PRcvr, pa, vable_a, vable_pa, pable_pa, fn2clos, fn2glob, fn2valmeth, fn2ptrmeth, fn2nil, ga, escapeArg, a2, square, intcallpanic, onetwothree)
 }
diff --git a/pkg/proc/eval.go b/pkg/proc/eval.go
index 1020c6c6..9d815178 100644
--- a/pkg/proc/eval.go
+++ b/pkg/proc/eval.go
@@ -23,8 +23,13 @@ var errOperationOnSpecialFloat = errors.New("operations on non-finite floats not
 
 // EvalExpression returns the value of the given expression.
 func (scope *EvalScope) EvalExpression(expr string, cfg LoadConfig) (*Variable, error) {
+	if scope.callCtx != nil {
+		// makes sure that the other goroutine won't wait forever if we make a mistake
+		defer close(scope.callCtx.continueRequest)
+	}
 	t, err := parser.ParseExpr(expr)
 	if err != nil {
+		scope.callCtx.doReturn(nil, err)
 		return nil, err
 	}
 
@@ -33,12 +38,14 @@ func (scope *EvalScope) EvalExpression(expr string, cfg LoadConfig) (*Variable,
 		ev, err = scope.evalAST(t)
 	}
 	if err != nil {
+		scope.callCtx.doReturn(nil, err)
 		return nil, err
 	}
 	ev.loadValue(cfg)
 	if ev.Name == "" {
 		ev.Name = expr
 	}
+	scope.callCtx.doReturn(ev, nil)
 	return ev, nil
 }
 
@@ -174,20 +181,11 @@ func (scope *EvalScope) evalAST(t ast.Expr) (*Variable, error) {
 	case *ast.CallExpr:
 		if len(node.Args) == 1 {
 			v, err := scope.evalTypeCast(node)
-			if err == nil {
-				return v, nil
-			}
-			_, isident := node.Fun.(*ast.Ident)
-			// we don't support function calls at the moment except for a few
-			// builtin functions so just return the type error here if the function
-			// isn't an identifier.
-			// More sophisticated logic will be required when function calls
-			// are implemented.
-			if err != reader.TypeNotFoundErr || !isident {
+			if err == nil || err != reader.TypeNotFoundErr {
 				return v, err
 			}
 		}
-		return scope.evalBuiltinCall(node)
+		return scope.evalFunctionCall(node)
 
 	case *ast.Ident:
 		return scope.evalIdent(node)
@@ -395,7 +393,7 @@ func convertInt(n uint64, signed bool, size int64) uint64 {
 func (scope *EvalScope) evalBuiltinCall(node *ast.CallExpr) (*Variable, error) {
 	fnnode, ok := node.Fun.(*ast.Ident)
 	if !ok {
-		return nil, fmt.Errorf("function calls are not supported")
+		return nil, nil
 	}
 
 	args := make([]*Variable, len(node.Args))
@@ -421,7 +419,7 @@ func (scope *EvalScope) evalBuiltinCall(node *ast.CallExpr) (*Variable, error) {
 		return realBuiltin(args, node.Args)
 	}
 
-	return nil, fmt.Errorf("function calls are not supported")
+	return nil, nil
 }
 
 func capBuiltin(args []*Variable, nodeargs []ast.Expr) (*Variable, error) {
diff --git a/pkg/proc/fncall.go b/pkg/proc/fncall.go
index ef0d3404..16d70de2 100644
--- a/pkg/proc/fncall.go
+++ b/pkg/proc/fncall.go
@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"go/ast"
 	"go/constant"
-	"go/parser"
 	"reflect"
 	"sort"
 
@@ -23,13 +22,18 @@ import (
 // The protocol is described in $GOROOT/src/runtime/asm_amd64.s in the
 // comments for function runtime·debugCallV1.
 //
-// There are two main entry points here. The first one is CallFunction which
-// evaluates a function call expression, sets up the function call on the
-// selected goroutine and resumes execution of the process.
+// The main entry point is EvalExpressionWithCalls which will start a goroutine to
+// evaluate the provided expression.
+// This goroutine can either return immediately, if no function calls were
+// needed, or write a continue request to the scope.callCtx.continueRequest
+// channel. When this happens EvalExpressionWithCalls will call Continue and
+// return.
 //
-// The second one is (*FunctionCallState).step() which is called every time
-// the process stops at a breakpoint inside one of the debug injcetion
-// functions.
+// The Continue loop will write to scope.callCtx.continueCompleted when it
+// hits a breakpoint in the call injection protocol.
+//
+// The work of setting up the function call and executing the protocol is
+// done by evalFunctionCall and funcCallStep.
 
 const (
 	debugCallFunctionNamePrefix1 = "debugCall"
@@ -49,17 +53,12 @@ var (
 	errNotEnoughArguments         = errors.New("not enough arguments")
 	errNoAddrUnsupported          = errors.New("arguments to a function call must have an address")
 	errNotAGoFunction             = errors.New("not a Go function")
+	errFuncCallNotAllowed         = errors.New("function calls not allowed without using 'call'")
 )
 
 type functionCallState struct {
-	// inProgress is true if a function call is in progress
-	inProgress bool
-	// finished is true if the function call terminated
-	finished bool
 	// savedRegs contains the saved registers
 	savedRegs Registers
-	// expr contains an expression describing the current function call
-	expr string
 	// err contains a saved error
 	err error
 	// fn is the function that is being called
@@ -77,21 +76,56 @@ type functionCallState struct {
 	panicvar *Variable
 }
 
-// CallFunction starts a debugger injected function call on the current thread of p.
-// See runtime.debugCallV1 in $GOROOT/src/runtime/asm_amd64.s for a
-// description of the protocol.
-func CallFunction(p Process, expr string, retLoadCfg *LoadConfig, checkEscape bool) error {
+type callContext struct {
+	p Process
+
+	// checkEscape is true if the escape check should be performed.
+	// See service/api.DebuggerCommand.UnsafeCall in service/api/types.go.
+	checkEscape bool
+
+	// retLoadCfg is the load configuration used to load return values
+	retLoadCfg LoadConfig
+
+	// Write to continueRequest to request a call to Continue from the
+	// debugger's main goroutine.
+	// Read from continueCompleted to wait for the target process to stop at
+	// one of the interaction point of the function call protocol.
+	// To signal that evaluation is completed a value will be written to
+	// continueRequest having cont == false and the return values in ret.
+	continueRequest   chan<- continueRequest
+	continueCompleted <-chan struct{}
+}
+
+type continueRequest struct {
+	cont bool
+	err  error
+	ret  *Variable
+}
+
+func (callCtx *callContext) doContinue() {
+	callCtx.continueRequest <- continueRequest{cont: true}
+	<-callCtx.continueCompleted
+}
+
+func (callCtx *callContext) doReturn(ret *Variable, err error) {
+	if callCtx == nil {
+		return
+	}
+	callCtx.continueRequest <- continueRequest{cont: false, ret: ret, err: err}
+}
+
+// EvalExpressionWithCalls is like EvalExpression but allows function calls in 'expr'.
+// Because this can only be done in the current goroutine, unlike
+// EvalExpression, EvalExpressionWithCalls is not a method of EvalScope.
+func EvalExpressionWithCalls(p Process, expr string, retLoadCfg LoadConfig, checkEscape bool) error {
 	bi := p.BinInfo()
 	if !p.Common().fncallEnabled {
 		return errFuncCallUnsupportedBackend
 	}
-	fncall := &p.Common().fncallState
-	if fncall.inProgress {
+	if p.Common().continueCompleted != nil {
 		return errFuncCallInProgress
 	}
 
-	*fncall = functionCallState{}
-
 	dbgcallfn := bi.LookupFunc[debugCallFunctionName]
 	if dbgcallfn == nil {
 		return errFuncCallUnsupported
@@ -106,49 +140,217 @@ func CallFunction(p Process, expr string, retLoadCfg *LoadConfig, checkEscape bo
 		return errGoroutineNotRunning
 	}
 
+	scope, err := GoroutineScope(p.CurrentThread())
+	if err != nil {
+		return err
+	}
+
+	continueRequest := make(chan continueRequest)
+	continueCompleted := make(chan struct{})
+
+	scope.callCtx = &callContext{
+		p:                 p,
+		checkEscape:       checkEscape,
+		retLoadCfg:        retLoadCfg,
+		continueRequest:   continueRequest,
+		continueCompleted: continueCompleted,
+	}
+
+	p.Common().continueRequest = continueRequest
+	p.Common().continueCompleted = continueCompleted
+
+	go scope.EvalExpression(expr, retLoadCfg)
+
+	contReq, ok := <-continueRequest
+	if contReq.cont {
+		return Continue(p)
+	}
+
+	return finishEvalExpressionWithCalls(p, contReq, ok)
+}
+
+func finishEvalExpressionWithCalls(p Process, contReq continueRequest, ok bool) error {
+	var err error
+	if !ok {
+		err = errors.New("internal error EvalExpressionWithCalls didn't return anything")
+	} else if contReq.err != nil {
+		if fpe, ispanic := contReq.err.(fncallPanicErr); ispanic {
+			p.CurrentThread().Common().returnValues = []*Variable{fpe.panicVar}
+		} else {
+			err = contReq.err
+		}
+	} else if contReq.ret.Addr == 0 && contReq.ret.DwarfType == nil {
+		// this is a variable returned by a function call with multiple return values
+		r := make([]*Variable, len(contReq.ret.Children))
+		for i := range contReq.ret.Children {
+			r[i] = &contReq.ret.Children[i]
+		}
+		p.CurrentThread().Common().returnValues = r
+	} else {
+		p.CurrentThread().Common().returnValues = []*Variable{contReq.ret}
+	}
+
+	p.Common().continueRequest = nil
+	close(p.Common().continueCompleted)
+	p.Common().continueCompleted = nil
+	return err
+}
+
+// evalFunctionCall evaluates a function call.
+// If this is a built-in function it's evaluated directly.
+// Otherwise this will start the function call injection protocol and
+// request that the target process resumes.
+// See the comment describing the field EvalScope.callCtx for a description
+// of the preconditions that make starting the function call protocol
+// possible.
+// See runtime.debugCallV1 in $GOROOT/src/runtime/asm_amd64.s for a
+// description of the protocol.
+func (scope *EvalScope) evalFunctionCall(node *ast.CallExpr) (*Variable, error) {
+	r, err := scope.evalBuiltinCall(node)
+	if r != nil || err != nil {
+		// it was a builtin call
+		return r, err
+	}
+	if scope.callCtx == nil {
+		return nil, errFuncCallNotAllowed
+	}
+
+	p := scope.callCtx.p
+	bi := scope.BinInfo
+	if !p.Common().fncallEnabled {
+		return nil, errFuncCallUnsupportedBackend
+	}
+	if p.Common().callInProgress {
+		return nil, errFuncCallInProgress
+	}
+
+	p.Common().callInProgress = true
+	defer func() {
+		p.Common().callInProgress = false
+	}()
+
+	dbgcallfn := bi.LookupFunc[debugCallFunctionName]
+	if dbgcallfn == nil {
+		return nil, errFuncCallUnsupported
+	}
+
+	// check that the selected goroutine is running
+	g := p.SelectedGoroutine()
+	if g == nil {
+		return nil, errNoGoroutine
+	}
+	if g.Status != Grunning || g.Thread == nil {
+		return nil, errGoroutineNotRunning
+	}
+
 	// check that there are at least 256 bytes free on the stack
 	regs, err := g.Thread.Registers(true)
 	if err != nil {
-		return err
+		return nil, err
 	}
 	regs = regs.Copy()
 	if regs.SP()-256 <= g.stacklo {
-		return errNotEnoughStack
+		return nil, errNotEnoughStack
 	}
 	_, err = regs.Get(int(x86asm.RAX))
 	if err != nil {
-		return errFuncCallUnsupportedBackend
+		return nil, errFuncCallUnsupportedBackend
 	}
 
-	fn, closureAddr, argvars, err := funcCallEvalExpr(p, expr)
+	fn, closureAddr, argvars, err := scope.funcCallEvalExpr(node)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
-	argmem, err := funcCallArgFrame(fn, argvars, g, bi, checkEscape)
+	argmem, err := funcCallArgFrame(fn, argvars, g, bi, scope.callCtx.checkEscape)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	if err := callOP(bi, g.Thread, regs, dbgcallfn.Entry); err != nil {
-		return err
+		return nil, err
 	}
 	// write the desired argument frame size at SP-(2*pointer_size) (the extra pointer is the saved PC)
 	if err := writePointer(bi, g.Thread, regs.SP()-3*uint64(bi.Arch.PtrSize()), uint64(len(argmem))); err != nil {
-		return err
+		return nil, err
 	}
 
-	fncall.inProgress = true
-	fncall.savedRegs = regs
-	fncall.expr = expr
-	fncall.fn = fn
-	fncall.closureAddr = closureAddr
-	fncall.argmem = argmem
-	fncall.retLoadCfg = retLoadCfg
+	fncall := functionCallState{
+		savedRegs:   regs,
+		fn:          fn,
+		closureAddr: closureAddr,
+		argmem:      argmem,
+		retLoadCfg:  &scope.callCtx.retLoadCfg,
+	}
 
 	fncallLog("function call initiated %v frame size %d\n", fn, len(argmem))
 
-	return Continue(p)
+	spoff := int64(scope.Regs.Uint64Val(scope.Regs.SPRegNum)) - int64(g.stackhi)
+	bpoff := int64(scope.Regs.Uint64Val(scope.Regs.BPRegNum)) - int64(g.stackhi)
+	fboff := scope.Regs.FrameBase - int64(g.stackhi)
+
+	for {
+		scope.callCtx.doContinue()
+
+		g = p.SelectedGoroutine()
+		if g != nil {
+			// adjust the value of registers inside scope
+			for regnum := range scope.Regs.Regs {
+				switch uint64(regnum) {
+				case scope.Regs.PCRegNum, scope.Regs.SPRegNum, scope.Regs.BPRegNum:
+					// leave these alone
+				default:
+					// every other register is dirty and unrecoverable
+					scope.Regs.Regs[regnum] = nil
+				}
+			}
+
+			scope.Regs.Regs[scope.Regs.SPRegNum].Uint64Val = uint64(spoff + int64(g.stackhi))
+			scope.Regs.Regs[scope.Regs.BPRegNum].Uint64Val = uint64(bpoff + int64(g.stackhi))
+			scope.Regs.FrameBase = fboff + int64(g.stackhi)
+			scope.Regs.CFA = scope.frameOffset + int64(g.stackhi)
+		}
+
+		finished := funcCallStep(scope, &fncall)
+		if finished {
+			break
+		}
+	}
+
+	if fncall.err != nil {
+		return nil, fncall.err
+	}
+
+	if fncall.panicvar != nil {
+		return nil, fncallPanicErr{fncall.panicvar}
+	}
+	switch len(fncall.retvars) {
+	case 0:
+		r := scope.newVariable("", 0, nil, nil)
+		r.loaded = true
+		r.Unreadable = errors.New("no return values")
+		return r, nil
+	case 1:
+		return fncall.retvars[0], nil
+	default:
+		// create a fake variable without address or type to return multiple values
+		r := scope.newVariable("", 0, nil, nil)
+		r.loaded = true
+		r.Children = make([]Variable, len(fncall.retvars))
+		for i := range fncall.retvars {
+			r.Children[i] = *fncall.retvars[i]
+		}
+		return r, nil
+	}
+}
+
+// fncallPanicErr is the error returned if a called function panics
+type fncallPanicErr struct {
+	panicVar *Variable
+}
+
+func (err fncallPanicErr) Error() string {
+	return fmt.Sprintf("panic calling a function")
 }
 
 func fncallLog(fmtstr string, args ...interface{}) {
@@ -191,21 +393,8 @@ func callOP(bi *BinaryInfo, thread Thread, regs Registers, callAddr uint64) erro
 
 // funcCallEvalExpr evaluates expr, which must be a function call, returns
 // the function being called and its arguments.
-func funcCallEvalExpr(p Process, expr string) (fn *Function, closureAddr uint64, argvars []*Variable, err error) {
-	bi := p.BinInfo()
-	scope, err := GoroutineScope(p.CurrentThread())
-	if err != nil {
-		return nil, 0, nil, err
-	}
-
-	t, err := parser.ParseExpr(expr)
-	if err != nil {
-		return nil, 0, nil, err
-	}
-	callexpr, iscall := t.(*ast.CallExpr)
-	if !iscall {
-		return nil, 0, nil, errNotACallExpr
-	}
+func (scope *EvalScope) funcCallEvalExpr(callexpr *ast.CallExpr) (fn *Function, closureAddr uint64, argvars []*Variable, err error) {
+	bi := scope.BinInfo
 
 	fnvar, err := scope.evalAST(callexpr.Fun)
 	if err != nil {
@@ -395,16 +584,16 @@ const (
 	debugCallAXRestoreRegisters = 16
 )
 
-func (fncall *functionCallState) step(p Process) {
+// funcCallStep executes one step of the function call injection protocol.
+func funcCallStep(scope *EvalScope, fncall *functionCallState) bool {
+	p := scope.callCtx.p
 	bi := p.BinInfo()
 
 	thread := p.CurrentThread()
 	regs, err := thread.Registers(false)
 	if err != nil {
 		fncall.err = err
-		fncall.finished = true
-		fncall.inProgress = false
-		return
+		return true
 	}
 	regs = regs.Copy()
 
@@ -453,7 +642,6 @@ func (fncall *functionCallState) step(p Process) {
 	case debugCallAXRestoreRegisters:
 		// runtime requests that we restore the registers (all except pc and sp),
 		// this is also the last step of the function call protocol.
-		fncall.finished = true
 		pc, sp := regs.PC(), regs.SP()
 		if err := thread.RestoreRegisters(fncall.savedRegs); err != nil {
 			fncall.err = fmt.Errorf("could not restore registers: %v", err)
@@ -467,6 +655,7 @@ func (fncall *functionCallState) step(p Process) {
 		if err := stepInstructionOut(p, thread, debugCallFunctionName, debugCallFunctionName); err != nil {
 			fncall.err = fmt.Errorf("could not step out of %s: %v", debugCallFunctionName, err)
 		}
+		return true
 
 	case debugCallAXReadReturn:
 		// read return arguments from stack
@@ -496,7 +685,7 @@ func (fncall *functionCallState) step(p Process) {
 	case debugCallAXReadPanic:
 		// read panic value from stack
 		if fncall.retLoadCfg == nil {
-			return
+			return false
 		}
 		fncall.panicvar, err = readTopstackVariable(thread, regs, "interface {}", *fncall.retLoadCfg)
 		if err != nil {
@@ -515,6 +704,8 @@ func (fncall *functionCallState) step(p Process) {
 		// possible is to ignore it and hope it didn't matter.
 		fncallLog("unknown value of AX %#x", rax)
 	}
+
+	return false
 }
 
 func readTopstackVariable(thread Thread, regs Registers, typename string, loadCfg LoadConfig) (*Variable, error) {
diff --git a/pkg/proc/interface.go b/pkg/proc/interface.go
index 9a4245a5..6362837b 100644
--- a/pkg/proc/interface.go
+++ b/pkg/proc/interface.go
@@ -115,8 +115,19 @@ type BreakpointManipulation interface {
 // implementations of the Process interface.
 type CommonProcess struct {
 	allGCache     []*G
-	fncallState   functionCallState
 	fncallEnabled bool
+
+	// if continueCompleted is not nil it means we are in the process of
+	// executing an injected function call, see comments throughout
+	// pkg/proc/fncall.go for a description of how this works.
+	continueCompleted chan<- struct{}
+	continueRequest   <-chan continueRequest
+
+	// callInProgress is true when a function call is being injected in the
+	// target process.
+	// This is only used to prevent nested function calls, it should be removed
+	// when we add support for them.
+	callInProgress bool
 }
 
 // NewCommonProcess returns a struct with fields common across
diff --git a/pkg/proc/proc.go b/pkg/proc/proc.go
index 85ef473f..1685b7f6 100644
--- a/pkg/proc/proc.go
+++ b/pkg/proc/proc.go
@@ -228,18 +228,18 @@ func Continue(dbp Process) error {
 				}
 				return conditionErrors(threads)
 			case strings.HasPrefix(loc.Fn.Name, debugCallFunctionNamePrefix1) || strings.HasPrefix(loc.Fn.Name, debugCallFunctionNamePrefix2):
-				fncall := &dbp.Common().fncallState
-				if !fncall.inProgress {
+				continueCompleted := dbp.Common().continueCompleted
+				if continueCompleted == nil {
 					return conditionErrors(threads)
 				}
-				fncall.step(dbp)
-				// only stop execution if the function call finished
-				if fncall.finished {
-					fncall.inProgress = false
-					if fncall.err != nil {
-						return fncall.err
+				continueCompleted <- struct{}{}
+				contReq, ok := <-dbp.Common().continueRequest
+				if !contReq.cont {
+					// only stop execution if the expression evaluation with calls finished
+					err := finishEvalExpressionWithCalls(dbp, contReq, ok)
+					if err != nil {
+						return err
 					}
-					curthread.Common().returnValues = fncall.returnValues()
 					return conditionErrors(threads)
 				}
 			default:
diff --git a/pkg/proc/proc_test.go b/pkg/proc/proc_test.go
index 5ef5a06c..2a73f8fe 100644
--- a/pkg/proc/proc_test.go
+++ b/pkg/proc/proc_test.go
@@ -4123,7 +4123,7 @@ func TestIssue1374(t *testing.T) {
 		setFileBreakpoint(p, t, fixture, 7)
 		assertNoError(proc.Continue(p), t, "First Continue")
 		assertLineNumber(p, t, 7, "Did not continue to correct location (first continue),")
-		assertNoError(proc.CallFunction(p, "getNum()", &normalLoadConfig, true), t, "Call")
+		assertNoError(proc.EvalExpressionWithCalls(p, "getNum()", normalLoadConfig, true), t, "Call")
 		err := proc.Continue(p)
 		if _, isexited := err.(proc.ErrProcessExited); !isexited {
 			regs, _ := p.CurrentThread().Registers(false)
@@ -4328,7 +4328,7 @@ func TestCallConcurrent(t *testing.T) {
 
 		gid1 := p.SelectedGoroutine().ID
 		t.Logf("starting injection in %d / %d", p.SelectedGoroutine().ID, p.CurrentThread().ThreadID())
-		assertNoError(proc.CallFunction(p, "Foo(10, 1)", &normalLoadConfig, false), t, "EvalExpressionWithCalls()")
+		assertNoError(proc.EvalExpressionWithCalls(p, "Foo(10, 1)", normalLoadConfig, false), t, "EvalExpressionWithCalls()")
 
 		returned := testCallConcurrentCheckReturns(p, t, gid1)
 
diff --git a/pkg/proc/variables.go b/pkg/proc/variables.go
index 3e83fa7f..ba143318 100644
--- a/pkg/proc/variables.go
+++ b/pkg/proc/variables.go
@@ -221,6 +221,20 @@ type EvalScope struct {
 	frameOffset int64
 
 	aordr *dwarf.Reader // extra reader to load DW_AT_abstract_origin entries, do not initialize
+
+	// When the following pointer is not nil this EvalScope was created
+	// by CallFunction and the expression evaluation is executing on a
+	// different goroutine from the debugger's main goroutine.
+	// Under this circumstance the expression evaluator can make function
+	// calls by setting up the runtime.debugCallV1 call and then writing a
+	// value to the continueRequest channel.
+	// When a value is written to continueRequest the debugger's main goroutine
+	// will call Continue, when the runtime in the target process sends us a
+	// request in the function call protocol the debugger's main goroutine will
+	// write a value to the continueCompleted channel.
+	// The goroutine executing the expression evaluation shall signal that the
+	// evaluation is complete by closing the continueRequest channel.
+	callCtx *callContext
 }
 
 // IsNilErr is returned when a variable is nil.
diff --git a/service/api/types.go b/service/api/types.go
index 0ac4f3d6..2bd6cf6f 100644
--- a/service/api/types.go
+++ b/service/api/types.go
@@ -311,7 +311,20 @@ type DebuggerCommand struct {
 	ReturnInfoLoadConfig *LoadConfig
 	// Expr is the expression argument for a Call command
 	Expr string `json:"expr,omitempty"`
-	// UnsafeCall disabled parameter escape checking for function calls
+
+	// UnsafeCall disables parameter escape checking for function calls.
+	// Go objects can be allocated on the stack or on the heap. Heap objects
+	// can be used by any goroutine; stack objects can only be used by the
+	// goroutine that owns the stack they are allocated on and can not surivive
+	// the stack frame of allocation.
+	// The Go compiler will use escape analysis to determine whether to
+	// allocate an object on the stack or the heap.
+	// When injecting a function call Delve will check that no address of a
+	// stack allocated object is passed to the called function: this ensures
+	// the rules for stack objects will not be violated.
+	// If you are absolutely sure that the function you are calling will not
+	// violate the rules about stack objects you can disable this safety check
+	// by setting UnsafeCall to true.
 	UnsafeCall bool `json:"unsafeCall,omitempty"`
 }
 
diff --git a/service/debugger/debugger.go b/service/debugger/debugger.go
index 74f05782..33020237 100644
--- a/service/debugger/debugger.go
+++ b/service/debugger/debugger.go
@@ -599,7 +599,10 @@ func (d *Debugger) Command(command *api.DebuggerCommand) (*api.DebuggerState, er
 		err = proc.Continue(d.target)
 	case api.Call:
 		d.log.Debugf("function call %s", command.Expr)
-		err = proc.CallFunction(d.target, command.Expr, api.LoadConfigToProc(command.ReturnInfoLoadConfig), !command.UnsafeCall)
+		if command.ReturnInfoLoadConfig == nil {
+			return nil, errors.New("can not call function with nil ReturnInfoLoadConfig")
+		}
+		err = proc.EvalExpressionWithCalls(d.target, command.Expr, *api.LoadConfigToProc(command.ReturnInfoLoadConfig), !command.UnsafeCall)
 	case api.Rewind:
 		d.log.Debug("rewinding")
 		if err := d.target.Direction(proc.Backward); err != nil {
diff --git a/service/test/integration2_test.go b/service/test/integration2_test.go
index f00ce682..252bb399 100644
--- a/service/test/integration2_test.go
+++ b/service/test/integration2_test.go
@@ -1584,6 +1584,7 @@ func TestClientServerFunctionCallBadPos(t *testing.T) {
 		state = <-c.Continue()
 		assertNoError(state.Err, t, "Continue()")
 
+		c.SetReturnValuesLoadConfig(&normalLoadConfig)
 		state, err = c.Call("main.call1(main.zero, main.zero)", false)
 		if err == nil || err.Error() != "call not at safe point" {
 			t.Fatalf("wrong error or no error: %v", err)
diff --git a/service/test/variables_test.go b/service/test/variables_test.go
index 421773ea..6c7c67d6 100644
--- a/service/test/variables_test.go
+++ b/service/test/variables_test.go
@@ -737,7 +737,7 @@ func TestEvalExpression(t *testing.T) {
 		{"i2 << i3", false, "", "", "int", fmt.Errorf("shift count type int, must be unsigned integer")},
 		{"*(i2 + i3)", false, "", "", "", fmt.Errorf("expression \"(i2 + i3)\" (int) can not be dereferenced")},
 		{"i2.member", false, "", "", "", fmt.Errorf("i2 (type int) is not a struct")},
-		{"fmt.Println(\"hello\")", false, "", "", "", fmt.Errorf("no type entry found, use 'types' for a list of valid types")},
+		{"fmt.Println(\"hello\")", false, "", "", "", fmt.Errorf("function calls not allowed without using 'call'")},
 		{"*nil", false, "", "", "", fmt.Errorf("nil can not be dereferenced")},
 		{"!nil", false, "", "", "", fmt.Errorf("operator ! can not be applied to \"nil\"")},
 		{"&nil", false, "", "", "", fmt.Errorf("can not take address of \"nil\"")},
@@ -1093,6 +1093,8 @@ func TestCallFunction(t *testing.T) {
 		outs []string // list of return parameters in this format: <param name>:<param type>:<param value>
 		err  error    // if not nil should return an error
 	}{
+		// Basic function call injection tests
+
 		{"call1(one, two)", []string{":int:3"}, nil},
 		{"call1(one+two, 4)", []string{":int:7"}, nil},
 		{"callpanic()", []string{`~panic:interface {}:interface {}(string) "callpanic panicked"`}, nil},
@@ -1102,6 +1104,13 @@ func TestCallFunction(t *testing.T) {
 		{`stringsJoin(s1, comma)`, nil, errors.New("could not find symbol value for s1")},
 		{`stringsJoin(intslice, comma)`, nil, errors.New("can not convert value of type []int to []string")},
 
+		// Expression tests
+		{`square(2) + 1`, []string{":int:5"}, nil},
+		{`intcallpanic(1) + 1`, []string{":int:2"}, nil},
+		{`intcallpanic(0) + 1`, []string{`~panic:interface {}:interface {}(string) "panic requested"`}, nil},
+		{`onetwothree(5)[1] + 2`, []string{":int:9"}, nil},
+
+		// Call types tests (methods, function pointers, etc.)
 		// The following set of calls was constructed using https://docs.google.com/document/d/1bMwCey-gmqZVTpRax-ESeVuZGmjwbocYs1iHplK-cjo/pub as a reference
 
 		{`a.VRcvr(1)`, []string{`:string:"1 + 3 = 4"`}, nil}, // direct call of a method with value receiver / on a value
@@ -1130,6 +1139,8 @@ func TestCallFunction(t *testing.T) {
 
 		{"ga.PRcvr(2)", []string{`:string:"2 - 0 = 2"`}, nil},
 
+		// Escape tests
+
 		{"escapeArg(&a2)", nil, errors.New("cannot use &a2 as argument pa2 in function main.escapeArg: stack object passed to escaping pointer: pa2")},
 
 		{"-unsafe escapeArg(&a2)", nil, nil}, // LEAVE THIS AS THE LAST ITEM, IT BREAKS THE TARGET PROCESS!!!
@@ -1151,9 +1162,9 @@ func TestCallFunction(t *testing.T) {
 				checkEscape = false
 			}
 			t.Logf("call %q", tc.expr)
-			err := proc.CallFunction(p, expr, &pnormalLoadConfig, checkEscape)
+			err := proc.EvalExpressionWithCalls(p, expr, pnormalLoadConfig, checkEscape)
 			if tc.err != nil {
-
+				t.Logf("\terr = %v\n", err)
 				if err == nil {
 					t.Fatalf("call %q: expected error %q, got no error", tc.expr, tc.err.Error())
 				}