diff --git a/include/string b/include/string
index 5bf42f023..1a7046794 100644
--- a/include/string
+++ b/include/string
@@ -3374,7 +3374,7 @@ basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(value_type __c,
     {
         const_pointer __p = data();
         const_pointer __pe = __p + __sz;
-        for (const_pointer __ps = __p + __pos; __p != __pe; ++__ps)
+        for (const_pointer __ps = __p + __pos; __ps != __pe; ++__ps)
             if (!traits_type::eq(*__ps, __c))
                 return static_cast<size_type>(__ps - __p);
     }
diff --git a/test/strings/basic.string/string.ops/string_find.first.not.of/char_size.pass.cpp b/test/strings/basic.string/string.ops/string_find.first.not.of/char_size.pass.cpp
index 88ce6b981..3be9e92d6 100644
--- a/test/strings/basic.string/string.ops/string_find.first.not.of/char_size.pass.cpp
+++ b/test/strings/basic.string/string.ops/string_find.first.not.of/char_size.pass.cpp
@@ -59,6 +59,8 @@ int main()
     test(S("oselktgbcapndfjihrmq"), 'q', 21, S::npos);
 
     test(S(""), 'q', S::npos);
+    test(S("q"), 'q', S::npos);
+    test(S("qqq"), 'q', S::npos);
     test(S("csope"), 'q', 0);
     test(S("gfsmthlkon"), 'q', 0);
     test(S("laenfsbridchgotmkqpj"), 'q', 0);