diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 61032872c6a..cd5e046ce52 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,3 +1,8 @@
+2015-08-21  Pedro Alves  <palves@redhat.com>
+
+	* ax.c (gdb_eval_agent_expr): Return expr_eval_unhandled_opcode
+	instead of literal 1.
+
 2015-08-21  Pedro Alves  <palves@redhat.com>
 
 	* tdesc.c (default_description): Explicitly zero-initialize.
diff --git a/gdb/gdbserver/ax.c b/gdb/gdbserver/ax.c
index c5b65fad62f..f94a27d96bb 100644
--- a/gdb/gdbserver/ax.c
+++ b/gdb/gdbserver/ax.c
@@ -1332,7 +1332,7 @@ gdb_eval_agent_expr (struct eval_agent_expr_context *ctx,
 		    op);
 	  /* If ever GDB generates any of these, we don't have the
 	     option of ignoring.  */
-	  return 1;
+	  return expr_eval_unhandled_opcode;
 
 	default:
 	  ax_debug ("Agent expression op 0x%x not recognized", op);