diff --git a/scripts/vim-patch.sh b/scripts/vim-patch.sh
index c2fac658a9..0854c2f627 100755
--- a/scripts/vim-patch.sh
+++ b/scripts/vim-patch.sh
@@ -280,49 +280,32 @@ preprocess_patch() {
 }
 
 uncrustify_patch() {
-  local commit="$1"
-  local changed_files=()
-  while IFS='' read -r file; do changed_files+=("$file"); done < <(git diff-tree --name-only --no-commit-id -r "${commit}")
+  git diff --quiet || {
+    >&2 echo 'Vim source working tree dirty, aborting.'
+    exit 1
+  }
 
   local patch_path=$NVIM_SOURCE_DIR/build/vim_patch
   rm -rf "$patch_path"
-  mkdir -p "$patch_path"/{before,after,patch}
+  mkdir -p "$patch_path"/{a,b}
 
-  git checkout --quiet "$commit"~
-  for file in "${changed_files[@]}"; do
-    if [[ -e $file ]]; then
-      cp "$file" "$patch_path"/before
-    fi
+  local commit="$1"
+  for file in $(git diff-tree --name-only --no-commit-id -r --diff-filter=a "$commit"); do
+    git --work-tree="$patch_path"/a checkout --quiet "$commit"~ -- "$file"
   done
-
-  git checkout --quiet "$commit"
-  for file in "${changed_files[@]}"; do
-    if [[ -e $file ]]; then
-      cp "$file" "$patch_path"/after
-    fi
+  for file in $(git diff-tree --name-only --no-commit-id -r --diff-filter=d "$commit"); do
+    git --work-tree="$patch_path"/b checkout --quiet "$commit" -- "$file"
   done
+  git reset --quiet --hard HEAD
 
   # If the difference are drastic enough uncrustify may need to be used more
   # than once. This is obviously a bug that needs to be fixed on uncrustify's
   # end, but in the meantime this workaround is sufficient.
   for _ in {1..2}; do
-    uncrustify -c "$NVIM_SOURCE_DIR"/src/uncrustify.cfg -q --replace --no-backup "$patch_path"/{before,after}/*.[ch]
+    uncrustify -c "$NVIM_SOURCE_DIR"/src/uncrustify.cfg -q --replace --no-backup "$patch_path"/{a,b}/src/*.[ch]
   done
 
-  for file in "${changed_files[@]}"; do
-    local basename
-    basename=$(basename "$file")
-    local before=$patch_path/before/$basename
-    local after=$patch_path/after/$basename
-    local patchfile="$patch_path"/patch/"$basename".patch
-    [[ ! -e $before ]] && before=/dev/null
-    [[ ! -e $after ]] && after=/dev/null
-    git --no-pager diff --no-index --patch --unified=5 --color=never "$before" "$after" > "$patchfile"
-    [[ "$before" != /dev/null ]] && sed -E "s|$before|/$file|g" -i "$patchfile"
-    [[ "$after" != /dev/null ]] && sed -E "s|$after|/$file|g" -i "$patchfile"
-  done
-
-  cat "$patch_path"/patch/*.patch
+  (cd "$patch_path" && (git --no-pager diff --no-index --no-prefix --patch --unified=5 --color=never a/ b/ || true))
 }
 
 get_vimpatch() {
@@ -335,7 +318,6 @@ get_vimpatch() {
   local patch_content
   if check_executable uncrustify; then
     patch_content="$(uncrustify_patch "${vim_commit}")"
-    git switch --quiet master
   else
     patch_content="$(git --no-pager show --unified=5 --color=never -1 --pretty=medium "${vim_commit}")"
   fi