diff --git a/.github/workflows/build_mac.yml b/.github/workflows/build_mac.yml
index a1cb488..7506266 100644
--- a/.github/workflows/build_mac.yml
+++ b/.github/workflows/build_mac.yml
@@ -21,7 +21,7 @@ jobs:
           MAC32_FLAGS:  "-fvisibility=hidden -rdynamic -DCC_BUILD_ICON"
           MAC64_FLAGS:  "-fvisibility=hidden -rdynamic -DCC_BUILD_ICON"
         run: |
-          LATEST_FLAG=-DCC_COMMIT_SHA=\"$(git rev-parse --short "$GITHUB_SHA")\"  
+          LATEST_FLAG=-DCC_COMMIT_SHA=\"${GITHUB_SHA::9}\"
           
           cd src
           MACOSX_DEPLOYMENT_TARGET=10.5 x86_64-apple-darwin9-cc *.c interop_cocoa.m ${{ env.COMMON_FLAGS }} ${{ env.MAC64_FLAGS }} $LATEST_FLAG -o cc-mac64-gl1 -framework Cocoa -framework OpenGL -framework IOKit -lobjc