diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index abac964224..33f02b6696 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -1083,9 +1083,9 @@ void LCodeGen::DoMathFloorOfDiv(LMathFloorOfDiv* instr) {
         static_cast<double>(static_cast<uint64_t>(1) << shift) / divisor_abs;
     int64_t multiplier;
     if (multiplier_f - floor(multiplier_f) < 0.5) {
-        multiplier = floor(multiplier_f);
+        multiplier = static_cast<int64_t>(floor(multiplier_f));
     } else {
-        multiplier = floor(multiplier_f) + 1;
+        multiplier = static_cast<int64_t>(floor(multiplier_f)) + 1;
     }
     // The multiplier is a uint32.
     ASSERT(multiplier > 0 &&
@@ -1096,7 +1096,7 @@ void LCodeGen::DoMathFloorOfDiv(LMathFloorOfDiv* instr) {
       __ test(dividend, dividend);
       DeoptimizeIf(zero, instr->environment());
     }
-    __ mov(edx, multiplier);
+    __ mov(edx, static_cast<int32_t>(multiplier));
     __ imul(edx);
     if (static_cast<int32_t>(multiplier) < 0) {
       __ add(edx, scratch);
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 4f71f83bf9..5d4316af1c 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -945,9 +945,9 @@ void LCodeGen::DoMathFloorOfDiv(LMathFloorOfDiv* instr) {
         static_cast<double>(static_cast<uint64_t>(1) << shift) / divisor_abs;
     int64_t multiplier;
     if (multiplier_f - floor(multiplier_f) < 0.5) {
-        multiplier = floor(multiplier_f);
+        multiplier = static_cast<int64_t>(floor(multiplier_f));
     } else {
-        multiplier = floor(multiplier_f) + 1;
+        multiplier = static_cast<int64_t>(floor(multiplier_f)) + 1;
     }
     // The multiplier is a uint32.
     ASSERT(multiplier > 0 &&