diff --git a/arm/cstart64.S b/arm/cstart64.S
index fcac9eb..62337a6 100644
--- a/arm/cstart64.S
+++ b/arm/cstart64.S
@@ -73,6 +73,12 @@
 	add     x5, x5, :lo12:stacktop
 	sub	x4, x5, #THREAD_SIZE
 	zero_range x4, x5
+
+	/* set SCTLR_EL1 to a known value */
+	ldr	x4, =INIT_SCTLR_EL1_MMU_OFF
+	msr	sctlr_el1, x4
+	isb
+
 	mov	x4, #1
 	msr	spsel, x4
 	adrp    x4, stackptr
diff --git a/lib/arm64/asm/sysreg.h b/lib/arm64/asm/sysreg.h
index 9d6b4fc..18c4ed3 100644
--- a/lib/arm64/asm/sysreg.h
+++ b/lib/arm64/asm/sysreg.h
@@ -8,6 +8,8 @@
 #ifndef _ASMARM64_SYSREG_H_
 #define _ASMARM64_SYSREG_H_
 
+#include <linux/const.h>
+
 #define sys_reg(op0, op1, crn, crm, op2) \
 	((((op0)&3)<<19)|((op1)<<16)|((crn)<<12)|((crm)<<8)|((op2)<<5))
 
@@ -87,4 +89,9 @@
 #define SCTLR_EL1_A	(1 << 1)
 #define SCTLR_EL1_M	(1 << 0)
 
+#define SCTLR_EL1_RES1	(_BITUL(7) | _BITUL(8) | _BITUL(11) | _BITUL(20) | \
+			 _BITUL(22) | _BITUL(23) | _BITUL(28) | _BITUL(29))
+#define INIT_SCTLR_EL1_MMU_OFF	\
+			SCTLR_EL1_RES1
+
 #endif /* _ASMARM64_SYSREG_H_ */