diff --git a/tools/aosp/aosp_sha.sh b/tools/aosp/aosp_sha.sh
index 29bf74c7a8b98..e50c70d0656a4 100755
--- a/tools/aosp/aosp_sha.sh
+++ b/tools/aosp/aosp_sha.sh
@@ -1,18 +1,24 @@
 #!/bin/bash
-LOCAL_DIR="$( dirname ${BASH_SOURCE} )"
+LOCAL_DIR="$( dirname "${BASH_SOURCE}" )"
 
-if git branch -vv | grep "^*" | grep "\[aosp/master" > /dev/null; then
+if git branch -vv | grep -q -P "^\*[^\[]+\[aosp/"; then
     # Change appears to be in AOSP
     exit 0
 else
     # Change appears to be non-AOSP; search for files
-    git show --name-only --pretty=format: $1 | grep $2 | while read file; do
-        echo
+    count=0
+    while read -r file ; do
+        if (( count == 0 )); then
+            echo
+        fi
         echo -e "\033[0;31mThe source of truth for '$file' is in AOSP.\033[0m"
+        (( count++ ))
+    done < <(git show --name-only --pretty=format: $1 | grep -- "$2")
+    if (( count != 0 )); then
         echo
-        echo "If your change contains no confidential details, please upload and merge"
-        echo "this change at https://android-review.googlesource.com/."
+        echo "If your change contains no confidential details (such as security fixes), please"
+        echo "upload and merge this change at https://android-review.googlesource.com/."
         echo
         exit 77
-    done
+    fi
 fi