diff --git a/get-changed-paths.sh b/get-changed-paths.sh
index 9d76745b..f6666158 100755
--- a/get-changed-paths.sh
+++ b/get-changed-paths.sh
@@ -69,12 +69,11 @@ function get_diff() {
   local base="$1"
   local sha="$2"
   local filter="$3"
-  local diff="${4:-$DIFF}"
 
   while IFS='' read -r sub; do
     sub_commit_pre="$(git diff "$base" "$sha" -- "$sub" | { grep '^[-]Subproject commit' || true; } | awk '{print $3}')" && exit_status=$? || exit_status=$?
     if [[ $exit_status -ne 0 ]]; then
-      echo "::error::Failed to get previous commit for submodule ($sub) between: $base$DIFF$sha"
+      echo "::error::Failed to get previous commit for submodule ($sub) between: $base $sha"
       return 1
     fi
 
@@ -88,13 +87,13 @@ function get_diff() {
       (
         cd "$sub" && (
           # the strange magic number is a hardcoded "empty tree" commit sha
-          get_diff "${sub_commit_pre:-4b825dc642cb6eb9a060e54bf8d69288fbee4904}" "${sub_commit_cur}" "$filter" ".." | awk -v r="$sub" '{ print "" r "/" $0}'
+          git diff --diff-filter="$filter" --name-only --ignore-submodules=all "${sub_commit_pre:-4b825dc642cb6eb9a060e54bf8d69288fbee4904}" "${sub_commit_cur}" | awk -v r="$sub" '{ print "" r "/" $0}'
         )
       )
     fi
   done < <(git submodule | awk '{print $2}')
 
-  git diff --diff-filter="$filter" --name-only --ignore-submodules=all "$base$diff$sha" && exit_status=$? || exit_status=$?
+  git diff --diff-filter="$filter" --name-only --ignore-submodules=all "$base$DIFF$sha" && exit_status=$? || exit_status=$?
 
   if [[ $exit_status -ne 0 ]]; then
     echo "::error::Failed to get changed files between: $base$DIFF$sha"