diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index 6557738..bbac7fe 100644
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -105,6 +105,7 @@
   ASSERT_EQ(99, WEXITSTATUS(status));
 
   ASSERT_EQ(expected, pthread_getspecific(key));
+  ASSERT_EQ(0, pthread_key_delete(key));
 }
 
 static void* DirtyKeyFn(void* key) {
@@ -132,6 +133,7 @@
   ASSERT_EQ(nullptr, result); // Not ~0!
 
   ASSERT_EQ(0, munmap(stack, stack_size));
+  ASSERT_EQ(0, pthread_key_delete(key));
 }
 
 static void* IdFn(void* arg) {