diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 930c15941157..640c11b25913 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -219,8 +219,8 @@ void alternative_msr_write(unsigned int msr, u64 val, unsigned int feature)
 {
 	asm volatile(ALTERNATIVE("", "wrmsr", %c[feature])
 		: : "c" (msr),
-		    "a" (val),
-		    "d" (val >> 32),
+		    "a" ((u32)val),
+		    "d" ((u32)(val >> 32)),
 		    [feature] "i" (feature)
 		: "memory");
 }