diff --git a/pythonx/UltiSnips/snippet/source/base.py b/pythonx/UltiSnips/snippet/source/base.py
index 4d6933f2..a7e4079f 100644
--- a/pythonx/UltiSnips/snippet/source/base.py
+++ b/pythonx/UltiSnips/snippet/source/base.py
@@ -15,6 +15,7 @@ class SnippetSource:
     def __init__(self):
         self._snippets = defaultdict(SnippetDictionary)
         self._extends = defaultdict(set)
+        self._must_refresh = True
 
     def ensure(self, filetypes):
         """Ensures that snippets are loaded."""
diff --git a/pythonx/UltiSnips/snippet/source/file/base.py b/pythonx/UltiSnips/snippet/source/file/base.py
index c3e00f3a..e36c142a 100644
--- a/pythonx/UltiSnips/snippet/source/file/base.py
+++ b/pythonx/UltiSnips/snippet/source/file/base.py
@@ -27,9 +27,11 @@ def __init__(self):
         SnippetSource.__init__(self)
 
     def ensure(self, filetypes):
-        for ft in self.get_deep_extends(filetypes):
-            if self._needs_update(ft):
-                self._load_snippets_for(ft)
+        if self._must_refresh:
+            for ft in self.get_deep_extends(filetypes):
+                if self._needs_update(ft):
+                    self._load_snippets_for(ft)
+            self._must_refresh = False
 
     def refresh(self):
         self.__init__()