diff --git a/contrib/ethereum/libethash/bit_manipulation.h b/contrib/ethereum/libethash/bit_manipulation.h
index 5c7baa79..4ba1033d 100644
--- a/contrib/ethereum/libethash/bit_manipulation.h
+++ b/contrib/ethereum/libethash/bit_manipulation.h
@@ -9,7 +9,7 @@
 #include "support/attributes.h"
 
 #include <stdint.h>
-#include <bitset>
+//#include <bitset>
 
 #ifdef __cplusplus
 extern "C" {
@@ -40,7 +40,7 @@ static inline uint32_t clz32(uint32_t x)
 
 static inline uint32_t popcount32(uint32_t x)
 {
-    return std::bitset<32>(x).count();
+  return (uint32_t)__builtin_popcount(x);
 }
 
 static inline uint32_t mul_hi32(uint32_t x, uint32_t y)