diff --git a/gn.spec b/gn.spec
index d9146c4..5916740 100644
--- a/gn.spec
+++ b/gn.spec
@@ -27,7 +27,7 @@ Name:           gn
 # See https://gn.googlesource.com/gn/+log for the latest changes.
 %global commit e0afadf7a743d5b14737bd454df45d5f1caf0d23
 %global access 20211205
-%global shortcommit %(echo %{commit} | cut -b -8)
+%global shortcommit %(c='%{commit}'; echo "${c:0:8}")
 Version:        1953
 Release:        %autorelease -s %{access}git%{shortcommit}
 Summary:        Meta-build system that generates build files for Ninja