diff --git a/src/system/kernel/arch/x86/32/arch.S b/src/system/kernel/arch/x86/32/arch.S
index 90ef56b363..68d7038be8 100644
--- a/src/system/kernel/arch/x86/32/arch.S
+++ b/src/system/kernel/arch/x86/32/arch.S
@@ -264,9 +264,12 @@ FUNCTION(arch_cpu_user_strlcpy):
 	/* count remaining bytes in src */
 .L_user_strlcpy_source_count:
 	not		%ecx
+		# %ecx was 0 and is now max
 	xor		%al,%al
+	movl	%esi,%edi
 	repnz
 	scasb
+	movl	%edi,%esi
 
 .L_user_strlcpy_source_done:
 	movl	%esi,%eax
diff --git a/src/system/kernel/arch/x86/64/arch.S b/src/system/kernel/arch/x86/64/arch.S
index 3f07b957d2..baf8d09f4e 100644
--- a/src/system/kernel/arch/x86/64/arch.S
+++ b/src/system/kernel/arch/x86/64/arch.S
@@ -251,9 +251,12 @@ FUNCTION(arch_cpu_user_strlcpy):
 .L_user_strlcpy_source_count:
 	// Count remaining bytes in src
 	not		%rcx
+		# %rcx was 0 and is now max
 	xor		%al, %al
+	movl	%rsi, %rdi
 	repnz
 	scasb
+	movl	%rdi, %rsi
 
 .L_user_strlcpy_source_done:
 	// Restore the old fault handler