diff --git a/diff-sha.sh b/diff-sha.sh
index 626a5cf2..56f16a9e 100644
--- a/diff-sha.sh
+++ b/diff-sha.sh
@@ -82,6 +82,8 @@ if [[ -z $GITHUB_BASE_REF ]]; then
         exit 1
       fi
     else
+      git fetch --no-tags -u --progress --depth="INPUT_FETCH_DEPTH" origin "$TARGET_BRANCH":"$TARGET_BRANCH"
+ 
       PREVIOUS_SHA=$(git rev-list --no-merges -n 1 "$TARGET_BRANCH" 2>&1) && exit_status=$? || exit_status=$?
       
       if [[ -z "$PREVIOUS_SHA" ]]; then
@@ -132,7 +134,7 @@ else
   CURRENT_BRANCH=$GITHUB_HEAD_REF
 
   if [[ -z $INPUT_BASE_SHA ]]; then
-    git fetch --no-tags -u --progress --depth=10 origin "$TARGET_BRANCH":"$TARGET_BRANCH"
+    git fetch --no-tags -u --progress --depth="INPUT_FETCH_DEPTH" origin "$TARGET_BRANCH":"$TARGET_BRANCH"
 
     PREVIOUS_SHA=$(git rev-list --no-merges -n 1 "$TARGET_BRANCH" 2>&1) && exit_status=$? || exit_status=$?
     if [[ -z "$PREVIOUS_SHA" ]]; then
@@ -140,7 +142,7 @@ else
     fi
     echo "::debug::Previous SHA: $PREVIOUS_SHA"
   else
-    git fetch --no-tags -u --progress --depth=10 origin "$INPUT_BASE_SHA" && exit_status=$? || exit_status=$?
+    git fetch --no-tags -u --progress --depth="INPUT_FETCH_DEPTH" origin "$INPUT_BASE_SHA" && exit_status=$? || exit_status=$?
     PREVIOUS_SHA=$INPUT_BASE_SHA && exit_status=$? || exit_status=$?
   fi