diff --git a/litex/soc/software/include/base/system.h b/litex/soc/software/include/base/system.h
index 014dbf47c..2a0d0c295 100644
--- a/litex/soc/software/include/base/system.h
+++ b/litex/soc/software/include/base/system.h
@@ -15,14 +15,14 @@ static inline unsigned long mfspr(unsigned long add)
 {
 	unsigned long ret;
 
-	__asm__ __volatile__ ("l.mfspr %0,r0,%1" : "=r" (ret) : "K" (add));
+	__asm__ __volatile__ ("l.mfspr %0,%1,0" : "=r" (ret) : "r" (add));
 
 	return ret;
 }
 
 static inline void mtspr(unsigned long add, unsigned long val)
 {
-	__asm__ __volatile__ ("l.mtspr r0,%1,%0" : : "K" (add), "r" (val));
+	__asm__ __volatile__ ("l.mtspr %0,%1,0" : : "r" (add), "r" (val));
 }
 #endif