diff --git a/js/src/jit/mips/MacroAssembler-mips.h b/js/src/jit/mips/MacroAssembler-mips.h
index 4fa2cec01930..3b329f2dd264 100644
--- a/js/src/jit/mips/MacroAssembler-mips.h
+++ b/js/src/jit/mips/MacroAssembler-mips.h
@@ -232,7 +232,7 @@ class MacroAssemblerMIPS : public Assembler
     void ma_b(Register lhs, ImmGCPtr imm, Label *l, Condition c, JumpKind jumpKind = LongJump) {
         MOZ_ASSERT(lhs != ScratchRegister);
         ma_li(ScratchRegister, imm);
-        ma_b(lhs, Imm32(uint32_t(imm.value)), l, c, jumpKind);
+        ma_b(lhs, ScratchRegister, l, c, jumpKind);
     }
     void ma_b(Register lhs, Address addr, Label *l, Condition c, JumpKind jumpKind = LongJump);
     void ma_b(Address addr, Imm32 imm, Label *l, Condition c, JumpKind jumpKind = LongJump);