diff --git a/libs/libc/string/lib_strchrnul.c b/libs/libc/string/lib_strchrnul.c
index ab15fb96004..d338efcc580 100644
--- a/libs/libc/string/lib_strchrnul.c
+++ b/libs/libc/string/lib_strchrnul.c
@@ -39,7 +39,7 @@
  *   considered to be part of the string.
  *
  * Returned Value:
- *   Upon completion, strchrnull() returns a pointer to the byte, or a
+ *   Upon completion, strchrnul() returns a pointer to the byte, or a
  *   pointer to null if the byte was not found.
  *
  ****************************************************************************/
diff --git a/libs/libc/string/lib_strrchr.c b/libs/libc/string/lib_strrchr.c
index 2a04b06c719..6c6b5d961e6 100644
--- a/libs/libc/string/lib_strrchr.c
+++ b/libs/libc/string/lib_strrchr.c
@@ -37,15 +37,16 @@
 #undef strrchr /* See mm/README.txt */
 FAR char *strrchr(FAR const char *s, int c)
 {
-  FAR const char *p = &s[strlen(s)];
+  FAR const char *r = NULL;
 
-  for (; p >= s; p--)
+  do
     {
-      if (*p == c)
+      if (*s == c)
         {
-          return (FAR char *)p;
+          r = s;
         }
     }
+  while (*s++ != '\0');
 
-  return NULL;
+  return (FAR char *)r;
 }