diff --git a/include/string.h b/include/string.h
index cd09513..ab9ba2d 100644
--- a/include/string.h
+++ b/include/string.h
@@ -77,8 +77,8 @@ void bcopy (const void *, void *, size_t);
 void bzero (void *, size_t);
 int strcasecmp (const char *, const char *);
 int strncasecmp (const char *, const char *, size_t);
-char *index (const char *, int);
-char *rindex (const char *, int);
+#define index(a,b) strchr((a),(b))
+#define rindex(a,b) strrchr((a),(b))
 int ffs (int);
 #endif
 
diff --git a/include/strings.h b/include/strings.h
index 345c651..f8fd255 100644
--- a/include/strings.h
+++ b/include/strings.h
@@ -17,8 +17,8 @@ void bzero (void *, size_t);
 
 int ffs (int);
 
-char *index (const char *, int);
-char *rindex (const char *, int);
+#define index(a,b) strchr((a),(b))
+#define rindex(a,b) strrchr((a),(b))
 
 int strcasecmp (const char *, const char *);
 int strncasecmp (const char *, const char *, size_t);