diff --git a/tools/aosp/aosp_sha.sh b/tools/aosp/aosp_sha.sh
index ac23c3d..36bea57 100755
--- a/tools/aosp/aosp_sha.sh
+++ b/tools/aosp/aosp_sha.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 LOCAL_DIR="$( dirname "${BASH_SOURCE}" )"
 
-if git branch -vv | grep -q -P "^\*[^\[]+\[aosp/"; then
+if git branch -vv | grep -q -E "^\*[^\[]+\[aosp/"; then
     # Change appears to be in AOSP
     exit 0
 elif git log -n 1 --format='%B' $1 | grep -q -E "^Ignore-AOSP-First: .+" ; then