diff --git a/tests/src/helpers.c b/tests/src/helpers.c
index 49a7df2989..936da066fb 100644
--- a/tests/src/helpers.c
+++ b/tests/src/helpers.c
@@ -375,7 +375,7 @@ void mbedtls_test_info_reset(void)
 #endif
 
 #ifdef MBEDTLS_THREADING_C
-    mbedtls_mutex_lock(&mbedtls_test_info_mutex);
+    mbedtls_mutex_unlock(&mbedtls_test_info_mutex);
 #endif /* MBEDTLS_THREADING_C */
 }