diff --git a/evm/src/cpu/kernel/asm/memory/syscalls.asm b/evm/src/cpu/kernel/asm/memory/syscalls.asm
index 082b44fa..3a233856 100644
--- a/evm/src/cpu/kernel/asm/memory/syscalls.asm
+++ b/evm/src/cpu/kernel/asm/memory/syscalls.asm
@@ -100,7 +100,8 @@ global sys_mstore8:
     // stack: expanded_num_bytes, kexit_info, offset, value
     %update_mem_bytes
     // stack: kexit_info, offset, value
-    %stack (kexit_info, offset, value) -> (offset, value, kexit_info)
+    %stack (kexit_info, offset, value) -> (value, 0x100, offset, kexit_info)
+    MOD SWAP1
     %mstore_current(@SEGMENT_MAIN_MEMORY)
     // stack: kexit_info
     EXIT_KERNEL
diff --git a/evm/src/cpu/kernel/asm/signed.asm b/evm/src/cpu/kernel/asm/signed.asm
index 7dd9c482..566d7d5a 100644
--- a/evm/src/cpu/kernel/asm/signed.asm
+++ b/evm/src/cpu/kernel/asm/signed.asm
@@ -183,32 +183,32 @@ global _sys_slt:
 
 global sys_sdiv:
     %charge_gas_const(@GAS_LOW)
-    %stack(x, y, kernel_return) -> (_sys_sdiv, x, y, _syscall_return, kernel_return)
+    %stack(kernel_return, x, y) -> (_sys_sdiv, x, y, _syscall_return, kernel_return)
     JUMP
 
 global sys_smod:
     %charge_gas_const(@GAS_LOW)
-    %stack(x, y, kernel_return) -> (_sys_smod, x, y, _syscall_return, kernel_return)
+    %stack(kernel_return, x, y) -> (_sys_smod, x, y, _syscall_return, kernel_return)
     JUMP
 
 global sys_signextend:
     %charge_gas_const(@GAS_LOW)
-    %stack(x, y, kernel_return) -> (_sys_signextend, x, y, _syscall_return, kernel_return)
+    %stack(kernel_return, x, y) -> (_sys_signextend, x, y, _syscall_return, kernel_return)
     JUMP
 
 global sys_sar:
     %charge_gas_const(@GAS_VERYLOW)
-    %stack(x, y, kernel_return) -> (_sys_sar, x, y, _syscall_return, kernel_return)
+    %stack(kernel_return, x, y) -> (_sys_sar, x, y, _syscall_return, kernel_return)
     JUMP
 
 global sys_slt:
     %charge_gas_const(@GAS_VERYLOW)
-    %stack(x, y, kernel_return) -> (_sys_slt, x, y, _syscall_return, kernel_return)
+    %stack(kernel_return, x, y) -> (_sys_slt, x, y, _syscall_return, kernel_return)
     JUMP
 
 global sys_sgt:
     %charge_gas_const(@GAS_VERYLOW)
-    %stack(x, y, kernel_return) -> (_sys_sgt, x, y, _syscall_return, kernel_return)
+    %stack(kernel_return, x, y) -> (_sys_sgt, x, y, _syscall_return, kernel_return)
     JUMP
 
 _syscall_return: