diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index 35108afc3b..be7851cdf8 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -4,6 +4,7 @@ Yii Framework 2 Change Log
 2.0.16 under development
 ------------------------
 
+- Bug #16081: Fixed composite IN using just one column (rugabarbo)
 - Bug #16926: Fix shell autocompletion (GHopperMSK)
 - Bug #15850: check basePath is writable on publish in AssetManager (Groonya)
 - Bug #16910: Fix messages sorting on extract (Groonya)
diff --git a/framework/db/conditions/InConditionBuilder.php b/framework/db/conditions/InConditionBuilder.php
index 87e4d8dca2..0424e039ac 100644
--- a/framework/db/conditions/InConditionBuilder.php
+++ b/framework/db/conditions/InConditionBuilder.php
@@ -50,12 +50,22 @@ class InConditionBuilder implements ExpressionBuilderInterface
             // ensure values is an array
             $values = (array) $values;
         }
-        if ($column instanceof \Traversable || ((is_array($column) || $column instanceof \Countable) && count($column) > 1)) {
-            return $this->buildCompositeInCondition($operator, $column, $values, $params);
-        }
 
         if (is_array($column)) {
-            $column = reset($column);
+            if (count($column) > 1) {
+                return $this->buildCompositeInCondition($operator, $column, $values, $params);
+            } else {
+                $column = reset($column);
+            }
+        }
+
+        if ($column instanceof \Traversable) {
+            if (iterator_count($column) > 1) {
+                return $this->buildCompositeInCondition($operator, $column, $values, $params);
+            } else {
+                $column->rewind();
+                $column = $column->current();
+            }
         }
 
         $sqlValues = $this->buildValues($expression, $values, $params);
@@ -88,6 +98,15 @@ class InConditionBuilder implements ExpressionBuilderInterface
         $sqlValues = [];
         $column = $condition->getColumn();
 
+        if (is_array($column)) {
+            $column = reset($column);
+        }
+
+        if ($column instanceof \Traversable) {
+            $column->rewind();
+            $column = $column->current();
+        }
+
         foreach ($values as $i => $value) {
             if (is_array($value) || $value instanceof \ArrayAccess) {
                 $value = isset($value[$column]) ? $value[$column] : null;
diff --git a/tests/framework/db/QueryBuilderTest.php b/tests/framework/db/QueryBuilderTest.php
index 154fd51caa..4cc200caa0 100644
--- a/tests/framework/db/QueryBuilderTest.php
+++ b/tests/framework/db/QueryBuilderTest.php
@@ -1130,6 +1130,19 @@ abstract class QueryBuilderTest extends DatabaseTestCase
                 '([[id]], [[name]]) IN ((:qp0, :qp1))',
                 [':qp0' => 1, ':qp1' => 'oy'],
             ],
+            'composite in (just one column)' => [
+                ['in', ['id'], [['id' => 1, 'name' => 'Name1'], ['id' => 2, 'name' => 'Name2']]],
+                '[[id]] IN (:qp0, :qp1)',
+                [':qp0' => 1, ':qp1' => 2],
+            ],
+            'composite in using array objects (just one column)' => [
+                ['in', new TraversableObject(['id']), new TraversableObject([
+                    ['id' => 1, 'name' => 'Name1'],
+                    ['id' => 2, 'name' => 'Name2'],
+                ])],
+                '[[id]] IN (:qp0, :qp1)',
+                [':qp0' => 1, ':qp1' => 2],
+            ],
 
             // in using array objects.
             [['id' => new TraversableObject([1, 2])], '[[id]] IN (:qp0, :qp1)', [':qp0' => 1, ':qp1' => 2]],