diff --git a/target/imagebuilder/files/Makefile b/target/imagebuilder/files/Makefile
index 3f919a0658..ee40612c1f 100644
--- a/target/imagebuilder/files/Makefile
+++ b/target/imagebuilder/files/Makefile
@@ -194,7 +194,7 @@ ifeq ($(CONFIG_USE_APK),)
 	if [ -d "$(PACKAGE_DIR)" ] && ( \
 			[ ! -f "$(PACKAGE_DIR)/Packages" ] || \
 			[ ! -f "$(PACKAGE_DIR)/Packages.gz" ] || \
-			[ "`find $(PACKAGE_DIR) -cnewer $(PACKAGE_DIR)/Packages.gz`" ] ); then \
+			[ "`find $(PACKAGE_DIR) -cnewer $(PACKAGE_DIR)/Packages.gz ! -name Packages.sig`" ] ); then \
 		echo "Package list missing or not up-to-date, generating it." >&2 ;\
 		$(MAKE) package_index; \
 	else \