diff --git a/testing/testsuite-targets.mk b/testing/testsuite-targets.mk
index d6f709c235f..2bc0b731605 100644
--- a/testing/testsuite-targets.mk
+++ b/testing/testsuite-targets.mk
@@ -131,7 +131,9 @@ endif
 
 package-tests:
 	$(NSINSTALL) -D $(DIST)/$(PKG_PATH)
-	@(cd $(PKG_STAGE) && tar $(TAR_CREATE_FLAGS) - *) | bzip2 -f > "$(DIST)/$(PKG_PATH)$(TEST_PACKAGE)"
+	@rm -f "$(DIST)/$(PKG_PATH)$(TEST_PACKAGE)"
+	cd $(PKG_STAGE) && \
+	  zip -r9D "../$(PKG_PATH)$(TEST_PACKAGE)" *
 
 make-stage-dir:
 	rm -rf $(PKG_STAGE) && $(NSINSTALL) -D $(PKG_STAGE) && $(NSINSTALL) -D $(PKG_STAGE)/bin && $(NSINSTALL) -D $(PKG_STAGE)/bin/components && $(NSINSTALL) -D $(PKG_STAGE)/certs
diff --git a/toolkit/mozapps/installer/package-name.mk b/toolkit/mozapps/installer/package-name.mk
index 675f958cbff..f85018d63c4 100644
--- a/toolkit/mozapps/installer/package-name.mk
+++ b/toolkit/mozapps/installer/package-name.mk
@@ -168,7 +168,7 @@ endif # MOZ_PKG_PRETTYNAMES
 SYMBOL_ARCHIVE_BASENAME = $(PKG_BASENAME).crashreporter-symbols
 
 # Test package naming
-TEST_PACKAGE = $(PKG_BASENAME).tests.tar.bz2
+TEST_PACKAGE = $(PKG_BASENAME).tests.zip
 
 ifneq (,$(wildcard $(DIST)/bin/application.ini))
 BUILDID = $(shell $(PYTHON) $(MOZILLA_DIR)/config/printconfigsetting.py $(DIST)/bin/application.ini App BuildID)