diff --git a/switch_all_submodules_to_head_and_clean b/switch_all_submodules_to_head_and_clean
index 5ca3d13..2c136fd 100755
--- a/switch_all_submodules_to_head_and_clean
+++ b/switch_all_submodules_to_head_and_clean
@@ -134,6 +134,7 @@ updateModule() {
                   (
                     cd $REPO_LOCALTREE &&
                     git fetch &&
+                    git worktree prune &&
                     git worktree add $PARENTDIR/$MODULE$submodule $branch &&
                     cd $PARENTDIR/$MODULE$submodule &&
                     git branch --set-upstream-to=origin/$branch