diff --git a/lang/qt/tests/Makefile.am b/lang/qt/tests/Makefile.am
index 65fd0196..0815984c 100644
--- a/lang/qt/tests/Makefile.am
+++ b/lang/qt/tests/Makefile.am
@@ -22,7 +22,7 @@
 GPG = gpg
 
 GNUPGHOME=$(abs_builddir)
-TESTS_ENVIRONMENT = GNUPGHOME=$(GNUPGHOME)
+TESTS_ENVIRONMENT = GNUPGHOME=$(GNUPGHOME) TZ=UTC
 
 EXTRA_DIST = initial.test final.test
 
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 99b6fb46..3ff86b6e 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -21,7 +21,7 @@
 ## Process this file with automake to produce Makefile.in
 
 GNUPGHOME=$(abs_builddir)
-TESTS_ENVIRONMENT = GNUPGHOME=$(GNUPGHOME)
+TESTS_ENVIRONMENT = GNUPGHOME=$(GNUPGHOME) TZ=UTC
 
 TESTS = t-version t-data t-engine-info