diff --git a/include/benchmark/benchmark_api.h b/include/benchmark/benchmark_api.h
index 664ca2a..b4aa21c 100644
--- a/include/benchmark/benchmark_api.h
+++ b/include/benchmark/benchmark_api.h
@@ -367,7 +367,7 @@
   }
 
   BENCHMARK_ALWAYS_INLINE
-  size_t complexity_length_n() {
+  int complexity_length_n() {
     return complexity_n_;
   }