diff --git a/src/modal.c b/src/modal.c
index df6f2f4..5dcd970 100644
--- a/src/modal.c
+++ b/src/modal.c
@@ -22,15 +22,6 @@ copy(char *src, char *dst, int length)
 	return dst;
 }
 
-static int
-slen(char *s)
-{
-	char *cap = s;
-	while(*cap++)
-		;
-	return cap - s;
-}
-
 static char *
 walk(char *s)
 {
@@ -272,8 +263,8 @@ static void
 remove_rule(Rule *r)
 {
 	if(r < rules_ - 1) {
-		int distance = slen(r->a) + slen(r->b);
 		char *memsrc = (r + 1)->a;
+		int distance = (r + 1)->a - r->a;
 		copy(memsrc, r->a, dict_ - memsrc);
 		while(r < rules_ - 1) {
 			Rule *next = r + 1;