diff --git a/debian/test.sh b/debian/test.sh
index 84242ffd6..1c3a59823 100755
--- a/debian/test.sh
+++ b/debian/test.sh
@@ -13,6 +13,9 @@ unset http_proxy
 unset https_proxy
 unset no_proxy
 
+# Some tests assume this isn't set
+unset SOURCE_DATE_EPOCH
+
 failed=0
 # Use line-buffering so stdout and stderr interleave somewhat nicely
 stdbuf -oL make check || failed=1
diff --git a/debian/tests/gnome-desktop-testing b/debian/tests/gnome-desktop-testing
index e4346cac9..5c118be18 100755
--- a/debian/tests/gnome-desktop-testing
+++ b/debian/tests/gnome-desktop-testing
@@ -11,6 +11,9 @@ unset http_proxy
 unset https_proxy
 unset no_proxy
 
+# Some tests assume this isn't set
+unset SOURCE_DATE_EPOCH
+
 tests="$(gnome-desktop-testing-runner -l libostree | while read -r t; do
 	t="${t%% *}"