diff --git a/Makefile.include b/Makefile.include
index 5b08f846328460bf5293bbc3769fc2c74553cfb2..7819fbf8dac8893abdb0ae7876a4ab6097971dd5 100644
--- a/Makefile.include
+++ b/Makefile.include
@@ -130,7 +130,7 @@ ifeq ($(origin RIOT_VERSION), undefined)
       RIOT_VERSION := $(GIT_STRING)-$(GIT_BRANCH)
     endif
   else
-    RIOT_VERSION := UNKNOWN (builddir: $(RIOTBASE))
+    RIOT_VERSION := "UNKNOWN (builddir: $(RIOTBASE))"
   endif
 endif
 export CFLAGS += -DRIOT_VERSION=\"$(RIOT_VERSION)\"