diff --git a/mercurial/manifest.py b/mercurial/manifest.py
--- a/mercurial/manifest.py
+++ b/mercurial/manifest.py
@@ -61,7 +61,7 @@
         if 64 < nl:
             # modern hash, full width
             yield f, bin(n[:64]), n[64:]
-        if 40 < nl < 45:
+        elif 40 < nl < 45:
             # legacy hash, always sha1
             yield f, bin(n[:40]), n[40:]
         else: