diff --git a/version.sh b/version.sh
index 40e8d05..e06443f 100755
--- a/version.sh
+++ b/version.sh
@@ -17,8 +17,8 @@
 # Note that the RELEASE-VERSION file should *not* be checked into git;
 # please add it to your top-level .gitignore file.
 
-version=$(git describe)
-if [ -n ${version} ]; then
+[ -d .git ] && version=$(git describe)
+if [ -n "${version}" ]; then
     # If we got something from git-describe, write the version to the
     # output file.
     echo ${version} > RELEASE-VERSION