diff --git a/build-mac.sh b/build-mac.sh
index 4068cceaf528..11505de547e2 100755
--- a/build-mac.sh
+++ b/build-mac.sh
@@ -16,6 +16,7 @@ export LIBRARY_PATH=$LIBRARY_PATH:/usr/local/lib:/usr/lib/
 if [ "$1" == "playback" ]
 then
         echo "Using Playback build config"
+        CMAKE_FLAGS+=" -DSLIPPI_PLAYBACK=true"
 else
         echo "Using Netplay build config"
         CMAKE_FLAGS+=" -DSLIPPI_PLAYBACK=false"