diff --git a/remotefilelog/lz4wrapper.py b/remotefilelog/lz4wrapper.py
--- a/remotefilelog/lz4wrapper.py
+++ b/remotefilelog/lz4wrapper.py
@@ -1,26 +1,29 @@
 from mercurial import error
 from mercurial.i18n import _
 
-import lz4
+from mercurial import demandimport
+demandimport.ignore.extend(['pkgutil', 'pkg_resources', '__main__'])
 
 def missing(*args, **kwargs):
     raise error.Abort(_('remotefilelog extension requires lz4 support'))
 
 lz4compress = lzcompresshc = lz4decompress = missing
 
-try:
-    # newer python-lz4 has these functions deprecated as top-level ones,
-    # so we are trying to import from lz4.block first
-    def _compressHC(*args, **kwargs):
-        return lz4.block.compress(*args, mode='high_compression', **kwargs)
-    lzcompresshc = _compressHC
-    lz4compress = lz4.block.compress
-    lz4decompress = lz4.block.decompress
-except (AttributeError, ImportError):
-    # ImportError is possible due to DemandImport
+with demandimport.deactivated():
+    import lz4
+
     try:
-        lzcompresshc = lz4.compressHC
-        lz4compress = lz4.compress
-        lz4decompress = lz4.decompress
-    except (AttributeError, ImportError):
-        pass
+        # newer python-lz4 has these functions deprecated as top-level ones,
+        # so we are trying to import from lz4.block first
+        def _compressHC(*args, **kwargs):
+            return lz4.block.compress(*args, mode='high_compression', **kwargs)
+        lzcompresshc = _compressHC
+        lz4compress = lz4.block.compress
+        lz4decompress = lz4.block.decompress
+    except AttributeError:
+        try:
+            lzcompresshc = lz4.compressHC
+            lz4compress = lz4.compress
+            lz4decompress = lz4.decompress
+        except AttributeError:
+            pass