diff --git a/app/Makefile.am b/app/Makefile.am
index 6a6648ddc2..2cbdef2fa8 100644
--- a/app/Makefile.am
+++ b/app/Makefile.am
@@ -279,13 +279,13 @@ git-version.h: update-git-version-header
 	  git_last_commit_timestamp=-1; \
 	  git_last_commit_year="`date --utc '+%Y'`"; \
 	fi; \
-	echo "#ifndef __GIT_VERSION_H__" > "$@.tmp"; \
-	echo "#define __GIT_VERSION_H__" >> "$@.tmp"; \
-	echo "#include <time.h>" >> "$@.tmp"; \
-	echo "#define GIMP_GIT_VERSION \"$$git_version\"" >> "$@.tmp"; \
-	echo "#define GIMP_GIT_LAST_COMMIT_TIMESTAMP ((time_t)$$git_last_commit_timestamp)" >> "$@.tmp"; \
-	echo "#define GIMP_GIT_LAST_COMMIT_YEAR \"$$git_last_commit_year\"" >> "$@.tmp"; \
-	echo "#endif /* __GIT_VERSION_H__ */" >> "$@.tmp"
+	if test -n "$$git_version"; then \
+	  echo "#ifndef __GIT_VERSION_H__" > "$@.tmp"; \
+	  echo "#define __GIT_VERSION_H__" >> "$@.tmp"; \
+	  echo "#define GIMP_GIT_VERSION \"$$git_version\"" >> "$@.tmp"; \
+	  echo "#define GIMP_GIT_LAST_COMMIT_YEAR \"$$git_last_commit_year\"" >> "$@.tmp"; \
+	  echo "#endif /* __GIT_VERSION_H__ */" >> "$@.tmp"; \
+	fi
 	@if ( test -f "$@.tmp" && test -f "$@" && cmp "$@.tmp" "$@" > /dev/null ); then \
 	  rm -f "$@.tmp"; \
 	elif test -f "$@.tmp"; then \