diff --git a/parallel_hashmap/phmap.h b/parallel_hashmap/phmap.h
index 8bdb15e..404ac22 100644
--- a/parallel_hashmap/phmap.h
+++ b/parallel_hashmap/phmap.h
@@ -2329,7 +2329,7 @@ class parallel_hash_set
         KeyArg<IsTransparent<Eq>::value && IsTransparent<Hash>::value>;
 
     static_assert(N <= 12, "N = 12 means 4096 hash tables!");
-    constexpr static size_t num_tables = 1 N;
+    constexpr static size_t num_tables = 1 << N;
     constexpr static size_t mask = num_tables - 1;
 
 public: