diff --git a/src/system/libroot/posix/pthread/pthread_key.cpp b/src/system/libroot/posix/pthread/pthread_key.cpp
index 431a4d4481..be251f71f1 100644
--- a/src/system/libroot/posix/pthread/pthread_key.cpp
+++ b/src/system/libroot/posix/pthread/pthread_key.cpp
@@ -35,7 +35,7 @@ get_key_destructor(uint32 key, int32& sequence)
 
 
 /*!	Function to get the thread specific value of a key in a lockless
-	way.
+	way. The thread specific value is reset to NULL.
 	\a sequence must be the sequence of the key table that this value
 	has to fit to.
 */
@@ -54,6 +54,8 @@ get_key_value(pthread_thread* thread, uint32 key, int32 sequence)
 		value = keyData.value;
 	} while (specificSequence != sequence);
 
+	keyData.value = NULL;
+
 	return value;
 }