diff --git a/scripts/modified-files.sh b/scripts/modified-files.sh
index 57bfe9e..1897b07 100755
--- a/scripts/modified-files.sh
+++ b/scripts/modified-files.sh
@@ -9,8 +9,11 @@ touch /tmp/swissknife/modified_files.txt
 
 FILES_MODIFIED=""
 get_modified_files() {
-    FILES_MODIFIED=""
-    FILES_MODIFIED=$(git diff --name-only $(git merge-base HEAD origin/${BASE_BRANCH})..HEAD)
+    if [[ "$CIRCLE_BRANCH" == "$BASE_BRANCH" ]]; then
+        FILES_MODIFIED=$(git diff --name-only HEAD HEAD~1)
+    else
+        FILES_MODIFIED=$(git diff --name-only $(git merge-base HEAD origin/${BASE_BRANCH})..HEAD)
+    fi
 }
 
 get_modified_files
diff --git a/src/commands/modified-files.yml b/src/commands/modified-files.yml
index 6732ed2..a78e539 100644
--- a/src/commands/modified-files.yml
+++ b/src/commands/modified-files.yml
@@ -1,5 +1,6 @@
 description: |
-  Finds all modified files for a given commit and base-branch
+  Finds all modified files for a given commit and base-branch.
+  This will only work on master branches if your team uses only squash merges.
 
 parameters:
   base-branch: