diff --git a/lark-stubs/reconstruct.pyi b/lark-stubs/reconstruct.pyi
index 9826428..a8d39e3 100644
--- a/lark-stubs/reconstruct.pyi
+++ b/lark-stubs/reconstruct.pyi
@@ -34,5 +34,6 @@ class Reconstructor:
     def __init__(self, parser: Lark, term_subs: Dict[str, Callable[[Symbol], str]] = ...):
         ...
 
-    def reconstruct(self, tree: Tree, postproc: Callable[[Iterable[str]], Iterable[str]]) -> str:
+    def reconstruct(self, tree: Tree, postproc: Callable[[Iterable[str]], Iterable[str]]=None,
+                    insert_spaces: bool = True) -> str:
         ...
diff --git a/lark/reconstruct.py b/lark/reconstruct.py
index 2efc0ae..ab2fb38 100644
--- a/lark/reconstruct.py
+++ b/lark/reconstruct.py
@@ -87,14 +87,14 @@ class Reconstructor(TreeMatcher):
             else:
                 yield item
 
-    def reconstruct(self, tree, postproc=None):
+    def reconstruct(self, tree, postproc=None, insert_spaces=True):
         x = self._reconstruct(tree)
         if postproc:
             x = postproc(x)
         y = []
         prev_item = ''
         for item in x:
-            if prev_item and item and is_id_continue(prev_item[-1]) and is_id_continue(item[0]):
+            if insert_spaces and prev_item and item and is_id_continue(prev_item[-1]) and is_id_continue(item[0]):
                 y.append(' ')
             y.append(item)
             prev_item = item