diff --git a/Makefile b/Makefile
index 24cdf3a..04599c2 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,16 @@
 
 all: abootimg
 
-abootimg: abootimg.c bootimg.h
-	echo '#define VERSION_STR "$(shell git describe --tags --abbrev=0)"' > version.h
+version.h:
+	if [ ! -f version.h ]; then \
+	if [ -d .git ]; then \
+	echo '#define VERSION_STR "$(shell git describe --tags --abbrev=0)"' > version.h; \
+	else \
+	echo '#define VERSION_STR ""' > version.h; \
+	fi \
+	fi
+
+abootimg: abootimg.c bootimg.h version.h
 	gcc -g -O2 -Wno-unused-result -o abootimg abootimg.c -DHAS_BLKID -lblkid
 
 clean: