diff --git a/rules-tests/CodeQuality/Rector/MethodCall/CallbackSingleAssertToSimplerRector/Fixture/single_stmt_void_callback.php.inc b/rules-tests/CodeQuality/Rector/MethodCall/CallbackSingleAssertToSimplerRector/Fixture/single_stmt_void_callback.php.inc
new file mode 100644
index 00000000..51e4ac57
--- /dev/null
+++ b/rules-tests/CodeQuality/Rector/MethodCall/CallbackSingleAssertToSimplerRector/Fixture/single_stmt_void_callback.php.inc
@@ -0,0 +1,41 @@
+<?php
+
+namespace Rector\PHPUnit\Tests\CodeQuality\Rector\MethodCall\CallbackSingleAssertToSimplerRector\Fixture;
+
+use PHPUnit\Framework\TestCase;
+
+final class SingleStmtVoidCallback extends TestCase
+{
+    public function test()
+    {
+        $builder = $this->getMockBuilder('AnyType')->getMock();
+
+        $builder->expects($this->once())
+            ->method('queueWebhooksByType')
+            ->with($this->callback(function ($type): void {
+                $this->assertSame($type, 'some_value');
+            }));
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\PHPUnit\Tests\CodeQuality\Rector\MethodCall\CallbackSingleAssertToSimplerRector\Fixture;
+
+use PHPUnit\Framework\TestCase;
+
+final class SingleStmtVoidCallback extends TestCase
+{
+    public function test()
+    {
+        $builder = $this->getMockBuilder('AnyType')->getMock();
+
+        $builder->expects($this->once())
+            ->method('queueWebhooksByType')
+            ->with($this->equalTo('some_value'));
+    }
+}
+
+?>
diff --git a/rules/CodeQuality/Rector/MethodCall/CallbackSingleAssertToSimplerRector.php b/rules/CodeQuality/Rector/MethodCall/CallbackSingleAssertToSimplerRector.php
index 67fd6c7a..47ad4978 100644
--- a/rules/CodeQuality/Rector/MethodCall/CallbackSingleAssertToSimplerRector.php
+++ b/rules/CodeQuality/Rector/MethodCall/CallbackSingleAssertToSimplerRector.php
@@ -133,14 +133,20 @@ private function matchCallbackSoleAssertSameExpected(Expr $expr): ?Expr
             }
         }
 
-        // exactly assertSame() expression + "return true;"
+        // sole assertSame() expression, optionally followed by "return true;"
         $closureStmts = $innerClosure->getStmts();
-        if (count($closureStmts) !== 2) {
+        if (count($closureStmts) === 2) {
+            [$firstStmt, $secondStmt] = $closureStmts;
+
+            if (! $secondStmt instanceof Return_ || ! $this->isTrueReturn($secondStmt)) {
+                return null;
+            }
+        } elseif (count($closureStmts) === 1) {
+            $firstStmt = $closureStmts[0];
+        } else {
             return null;
         }
 
-        [$firstStmt, $secondStmt] = $closureStmts;
-
         if (! $firstStmt instanceof Expression) {
             return null;
         }
@@ -150,10 +156,6 @@ private function matchCallbackSoleAssertSameExpected(Expr $expr): ?Expr
             return null;
         }
 
-        if (! $secondStmt instanceof Return_ || ! $this->isTrueReturn($secondStmt)) {
-            return null;
-        }
-
         $assertSameArgs = $firstStmtExpr->getArgs();
         if (count($assertSameArgs) !== 2) {
             return null;