diff --git a/binary_patch.py b/binary_patch.py
index c75c781..2616014 100644
--- a/binary_patch.py
+++ b/binary_patch.py
@@ -76,13 +76,10 @@ def patch_strcpy(nbytes, save_path, output=True):
     push rcx;
     push rdx;
     xor rcx, rcx;
-  loop:
     mov rdx, {nbytes-1};
-    mov al, [rcx + rsi];
-    
-    cmp rcx, rdx;
-    jge ret_code;
-
+    mov byte ptr [rdx + rsi], 0;
+  loop:
+    mov al, [rsi + rcx];
     test al, al;
     je ret_code;
     
@@ -90,7 +87,7 @@ def patch_strcpy(nbytes, save_path, output=True):
     
     inc rcx;
     jmp loop;
-    
+
   ret_code:
     mov [rsi + rcx], al;
     pop rdx;