diff --git a/headers/posix/arch/arm/arch_setjmp.h b/headers/posix/arch/arm/arch_setjmp.h
index 2a86ea60ac..a2ce56e36b 100644
--- a/headers/posix/arch/arm/arch_setjmp.h
+++ b/headers/posix/arch/arm/arch_setjmp.h
@@ -5,8 +5,7 @@
 #ifndef _ARCH_SETJMP_H_
 #define _ARCH_SETJMP_H_
 
-#define _SETJMP_BUF_SZ (7+6+2+8*((96/8)/4))
+#define _SETJMP_BUF_SZ ((15+2)*4)
 typedef int __jmp_buf[_SETJMP_BUF_SZ];
-#warning ARM: fix jmpbuf size
 
 #endif	/* _ARCH_SETJMP_H_ */
diff --git a/src/system/libroot/posix/arch/arm/sigsetjmp.S b/src/system/libroot/posix/arch/arm/sigsetjmp.S
index 14bab2ef88..a0f59ad758 100644
--- a/src/system/libroot/posix/arch/arm/sigsetjmp.S
+++ b/src/system/libroot/posix/arch/arm/sigsetjmp.S
@@ -10,6 +10,7 @@
 /* int sigsetjmp(jmp_buf buffer, int saveMask) */
 FUNCTION(__sigsetjmp):
 FUNCTION(sigsetjmp):
+	stmdb   sp!, {r4, lr}
         stmia   r0, {r0-r14}
         str     lr,[r0, #60]
         mrs     r1,cpsr
@@ -18,19 +19,21 @@ FUNCTION(sigsetjmp):
         mov     r0, #0
 
 	bl		__setjmp_save_sigs
+	ldmia   sp!, {r4, pc}
 FUNCTION_END(__sigsetjmp)
 FUNCTION_END(sigsetjmp)
 
 
 /* int setjmp(jmp_buf buffer) */
 FUNCTION(setjmp):
+	stmdb   sp!, {r4, lr}
         stmia   r0, {r0-r14}
         str     lr,[r0, #60]
         mrs     r1,cpsr
         str     r1,[r0,#64]
         ldr     r1,[r0,#4]
         mov     r0, #0
-	bl	__sigsetjmp
+	ldmia   sp!, {r4, pc}
 FUNCTION_END(setjmp)
 
 #pragma weak _setjmp=setjmp