diff --git a/string.asm b/string.asm
index 6a06be5..d3905b2 100644
--- a/string.asm
+++ b/string.asm
@@ -1021,12 +1021,14 @@ lb2a     short M                        copy characters 'til the null is found
          ldy   #0
          ldx   n
          beq   lb4
-         bmi   lb4
 lb3      lda   [s2],Y
          sta   [s1],Y
          beq   lb4
          iny
-         dex
+         bne   lb3a
+         inc   s1+2
+         inc   s2+2
+lb3a     dex
          bne   lb3
          lda   n+2
          beq   lb4