diff --git a/libiberty/strstr.c b/libiberty/strstr.c
index c6f68495a33..49209e8229f 100644
--- a/libiberty/strstr.c
+++ b/libiberty/strstr.c
@@ -18,18 +18,23 @@ length, the function returns @var{string}.
 
 #include <stddef.h>
 
-extern int memcmp (const void *, const void *, size_t);
+extern char *strchr (const char *, int);
+extern int strncmp (const void *, const void *, size_t);
 extern size_t strlen (const char *);
 
 char *
 strstr (const char *s1, const char *s2)
 {
+  const char *p = s1;
   const size_t len = strlen (s2);
-  while (*s1)
+
+  if (!len)
+    return s1;
+
+  for (; (p = strchr (p, *s2)) != 0; p++)
     {
-      if (!memcmp (s1, s2, len))
-	return (char *)s1;
-      ++s1;
+      if (strncmp (p, s2, len) == 0)
+	return (char *)p;
     }
   return (0);
 }