diff --git a/usr.bin/diff/diffreg.c b/usr.bin/diff/diffreg.c
--- a/usr.bin/diff/diffreg.c
+++ b/usr.bin/diff/diffreg.c
@@ -1462,7 +1462,7 @@
 
 	printf("***************");
 	if (flags & (D_PROTOTYPE | D_MATCHLAST)) {
-		f = match_function(ixold, lowa - 1, f1);
+		f = match_function(ixold, cvp->a - 1, f1);
 		if (f != NULL)
 			printf(" %s", f);
 	}
@@ -1569,7 +1569,7 @@
 	uni_range(lowc, upd);
 	printf(" @@");
 	if (flags & (D_PROTOTYPE | D_MATCHLAST)) {
-		f = match_function(ixold, lowa - 1, f1);
+		f = match_function(ixold, cvp->a - 1, f1);
 		if (f != NULL)
 			printf(" %s", f);
 	}