diff --git a/make/defs.mk b/make/defs.mk
index efc6ec20..a54d3fb4 100644
--- a/make/defs.mk
+++ b/make/defs.mk
@@ -179,7 +179,7 @@ PKG_VENDOR                  ?= janware GmbH
 
 # ----- packaging variables
 
-ifneq ($(filter debian%,$(OS_NAME_VERSION)),)
+ifneq ($(findstring $(OS_NAME),debian ubuntu),)
   PKG_FORMAT                ?= debian
 else
   PKG_FORMAT                ?= rpm