diff --git a/src/common/classes/auto.h b/src/common/classes/auto.h
index fffbb61c736..cc4d59b973f 100644
--- a/src/common/classes/auto.h
+++ b/src/common/classes/auto.h
@@ -132,6 +132,7 @@ class AutoPtr
 	{
 		if (this != &r)
 		{
+			Clear<Where>::clear(ptr);
 			ptr = r.ptr;
 			r.ptr = nullptr;
 		}
diff --git a/src/common/tests/AutoPtrTests.cpp b/src/common/tests/AutoPtrTests.cpp
new file mode 100644
index 00000000000..765f3ad3f5f
--- /dev/null
+++ b/src/common/tests/AutoPtrTests.cpp
@@ -0,0 +1,44 @@
+#include "boost/test/unit_test.hpp"
+#include "../common/classes/auto.h"
+
+using namespace Firebird;
+
+BOOST_AUTO_TEST_SUITE(CommonClassesSuite)
+BOOST_AUTO_TEST_SUITE(AutoPtrFunctionalTests)
+
+static int aliveCounter = 0;
+
+class TestRefCounter
+{
+public:
+	TestRefCounter()
+	{
+		++aliveCounter;
+	}
+	~TestRefCounter()
+	{
+		--aliveCounter;
+	}
+};
+
+AutoPtr<TestRefCounter> makePtr()
+{
+	return AutoPtr<TestRefCounter>(new TestRefCounter());
+}
+
+BOOST_AUTO_TEST_CASE(StringAssignmentTest)
+{
+	AutoPtr<TestRefCounter> ptr;
+
+	ptr = makePtr();
+
+	ptr = makePtr();
+
+	ptr.reset();
+
+	BOOST_TEST(aliveCounter == 0);
+}
+
+
+BOOST_AUTO_TEST_SUITE_END() // AutoPtrFunctionalTests
+BOOST_AUTO_TEST_SUITE_END()	// CommonClassesSuite