1 files changed, 1 insertions, 1 deletions

diff --git a/src/fns.c b/src/fns.c
index 1bcb963e20f..2e282011e75 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -153,7 +153,7 @@ which is at least the number of distinct elements.")
       if (EQ (tail, halftail) && len != 0)
         break;
       len++;
-      if (len & 1 == 0)
+      if ((len & 1) == 0)
         halftail = XCONS (halftail)->cdr;
     }