diff --git a/src/libstrongswan/tests/test_utils.c b/src/libstrongswan/tests/test_utils.c
index ec9baf158..811882e53 100644
--- a/src/libstrongswan/tests/test_utils.c
+++ b/src/libstrongswan/tests/test_utils.c
@@ -18,6 +18,8 @@
 #include <library.h>
 #include <utils/utils.h>
 
+#include <time.h>
+
 /*******************************************************************************
  * object storage on lib
  */
@@ -391,6 +393,10 @@ Suite *utils_suite_create()
 	Suite *s;
 	TCase *tc;
 
+	/* force a timezone to match non-UTC conversions */
+	setenv("TZ", "Europe/Zurich", 1);
+	tzset();
+
 	s = suite_create("utils");
 
 	tc = tcase_create("objects");