diff --git a/litex/soc/cores/cpu/microwatt/crt0.S b/litex/soc/cores/cpu/microwatt/crt0.S
index 5fc295f1b..cfd670170 100644
--- a/litex/soc/cores/cpu/microwatt/crt0.S
+++ b/litex/soc/cores/cpu/microwatt/crt0.S
@@ -76,10 +76,9 @@ _start:
 	bdnz	0b
 1:
 	/* setup stack */
-	LOAD_IMM64(%r1, _fstack - 0x100)
-	LOAD_IMM64(%r12, main)
-	mtctr	%r12,
-	bctrl
+	ld	%r1,_fstack@got(%r2)
+	subi  %r1,%r1,0x100
+	bl	main
 	b .
 
 #define EXCEPTION(nr)		\