diff --git a/src/codegen/mips/macro-assembler-mips.cc b/src/codegen/mips/macro-assembler-mips.cc
index 909425360e..dcf7b60afd 100644
--- a/src/codegen/mips/macro-assembler-mips.cc
+++ b/src/codegen/mips/macro-assembler-mips.cc
@@ -2091,7 +2091,8 @@ void TurboAssembler::RoundFloat(FPURegister dst, FPURegister src,
     Ext(at, scratch, kFloat32MantissaBits, kFloat32ExponentBits);
     Branch(USE_DELAY_SLOT, &done, hs, at,
            Operand(kFloat32ExponentBias + kFloat32MantissaBits));
-    mov_s(dst, src);
+    // Canonicalize the result.
+    sub_s(dst, src, kDoubleRegZero);
     round(this, dst, src);
     mfc1(at, dst);
     Branch(USE_DELAY_SLOT, &done, ne, at, Operand(zero_reg));
diff --git a/src/codegen/mips64/macro-assembler-mips64.cc b/src/codegen/mips64/macro-assembler-mips64.cc
index 902930045e..feda79e6c8 100644
--- a/src/codegen/mips64/macro-assembler-mips64.cc
+++ b/src/codegen/mips64/macro-assembler-mips64.cc
@@ -2513,7 +2513,8 @@ void TurboAssembler::RoundDouble(FPURegister dst, FPURegister src,
     Ext(at, scratch, HeapNumber::kExponentShift, HeapNumber::kExponentBits);
     Branch(USE_DELAY_SLOT, &done, hs, at,
            Operand(HeapNumber::kExponentBias + HeapNumber::kMantissaBits));
-    mov_d(dst, src);
+    // Canonicalize the result.
+    sub_d(dst, src, kDoubleRegZero);
     round(this, dst, src);
     dmfc1(at, dst);
     Branch(USE_DELAY_SLOT, &done, ne, at, Operand(zero_reg));
@@ -2573,7 +2574,8 @@ void TurboAssembler::RoundFloat(FPURegister dst, FPURegister src,
     Ext(at, scratch, kFloat32MantissaBits, kFloat32ExponentBits);
     Branch(USE_DELAY_SLOT, &done, hs, at,
            Operand(kFloat32ExponentBias + kFloat32MantissaBits));
-    mov_s(dst, src);
+    // Canonicalize the result.
+    sub_s(dst, src, kDoubleRegZero);
     round(this, dst, src);
     mfc1(at, dst);
     Branch(USE_DELAY_SLOT, &done, ne, at, Operand(zero_reg));