diff --git a/libraries/chain/include/eosio/chain/webassembly/interface.hpp b/libraries/chain/include/eosio/chain/webassembly/interface.hpp
index 39093ddeb2..ded9ae59a2 100644
--- a/libraries/chain/include/eosio/chain/webassembly/interface.hpp
+++ b/libraries/chain/include/eosio/chain/webassembly/interface.hpp
@@ -1928,7 +1928,7 @@ namespace webassembly {
          void __lshrti3(legacy_ptr<int128_t>, uint64_t, uint64_t, uint32_t) const;
          void __divti3(legacy_ptr<int128_t>, uint64_t, uint64_t, uint64_t, uint64_t) const;
          void __udivti3(legacy_ptr<uint128_t>, uint64_t, uint64_t, uint64_t, uint64_t) const;
-         void __multi3(legacy_ptr<int128_t>, uint64_t, uint64_t, uint64_t, uint64_t) const;
+         void __multi3(legacy_ptr<uint128_t>, uint64_t, uint64_t, uint64_t, uint64_t) const;
          void __modti3(legacy_ptr<int128_t>, uint64_t, uint64_t, uint64_t, uint64_t) const;
          void __umodti3(legacy_ptr<uint128_t>, uint64_t, uint64_t, uint64_t, uint64_t) const;
          void __addtf3(legacy_ptr<float128_t>, uint64_t, uint64_t, uint64_t, uint64_t) const;
diff --git a/libraries/chain/webassembly/compiler_builtins.cpp b/libraries/chain/webassembly/compiler_builtins.cpp
index 2ccda54da4..9ed61147b3 100644
--- a/libraries/chain/webassembly/compiler_builtins.cpp
+++ b/libraries/chain/webassembly/compiler_builtins.cpp
@@ -72,9 +72,9 @@ namespace eosio { namespace chain { namespace webassembly {
       *ret = lhs;
    }
 
-   void interface::__multi3(legacy_ptr<__int128> ret, uint64_t la, uint64_t ha, uint64_t lb, uint64_t hb) const {
-      __int128 lhs = ha;
-      __int128 rhs = hb;
+   void interface::__multi3(legacy_ptr<uint128_t> ret, uint64_t la, uint64_t ha, uint64_t lb, uint64_t hb) const {
+      uint128_t lhs = ha;
+      uint128_t rhs = hb;
 
       lhs <<= 64;
       lhs |=  la;