diff --git a/README.md b/README.md
index 8cf1254..f50f1cf 100644
--- a/README.md
+++ b/README.md
@@ -383,6 +383,25 @@ struct foo
 };
 ```
 
+If the member is defined outside of the class, use `TICK_MEMBER_REQUIRES_OC` (OC: outside_class) outside the class. For example,
+```cpp
+template<class T>
+struct foo
+{
+    T x;
+
+    TICK_MEMBER_REQUIRES(is_incrementable<T>())
+    void up();
+};
+
+template<class T>
+TICK_MEMBER_REQUIRES_OC(is_incrementable<T>())
+void foo<T>::up()
+{
+    x++;
+}
+```
+
 TICK_PARAM_REQUIRES
 --------------------
 
diff --git a/doc/src/requires.md b/doc/src/requires.md
index 2d2d9dc..53d455c 100644
--- a/doc/src/requires.md
+++ b/doc/src/requires.md
@@ -57,6 +57,25 @@ struct foo
 };
 ```
 
+If the member is defined outside of the class, use `TICK_MEMBER_REQUIRES_OC` (OC: outside_class) outside the class. For example,
+```cpp
+template<class T>
+struct foo
+{
+    T x;
+
+    TICK_MEMBER_REQUIRES(is_incrementable<T>())
+    void up();
+};
+
+template<class T>
+TICK_MEMBER_REQUIRES_OC(is_incrementable<T>())
+void foo<T>::up()
+{
+    x++;
+}
+```
+
 TICK_PARAM_REQUIRES
 --------------------
 
diff --git a/test/requires.cpp b/test/requires.cpp
index eb2a468..01b5b05 100644
--- a/test/requires.cpp
+++ b/test/requires.cpp
@@ -3,6 +3,7 @@
 #include <type_traits>
 #include <tick/integral_constant.h>
 #include <tick/requires.h>
+#include <cassert>
 
 struct not_int {};
 
@@ -163,3 +164,36 @@ TICK_STATIC_TEST_CASE()
     STATIC_ASSERT_SAME(decltype(check_param_trait_requires(not_int())), std::false_type);
 };
 
+
+
+template<class T>
+struct member_requires_oc
+{
+    T x;
+
+    TICK_MEMBER_REQUIRES(std::is_same<T, int>::value)
+    int foo();
+
+    TICK_MEMBER_REQUIRES(std::is_same<T, char>::value)
+    char foo();
+};
+
+template<class T>
+TICK_MEMBER_REQUIRES_OC(std::is_same<T, int>::value)
+int member_requires_oc<T>::foo()
+{
+    return 123;
+}
+
+template<class T>
+TICK_MEMBER_REQUIRES_OC(std::is_same<T, char>::value)
+char member_requires_oc<T>::foo()
+{
+    return 'a';
+}
+
+TICK_TEST_CASE()
+{
+    assert(member_requires_oc<int>().foo() == 123);
+    assert(member_requires_oc<char>().foo() == 'a');
+}
diff --git a/tick/requires.h b/tick/requires.h
index 7604bc4..a1a6507 100644
--- a/tick/requires.h
+++ b/tick/requires.h
@@ -53,9 +53,11 @@ trait(Ts&&...) noexcept
 
 #define TICK_CLASS_REQUIRES(...) typename std::enable_if<(__VA_ARGS__)>::type
 
-#define TICK_REQUIRES(...) bool TickPrivateBool ## __LINE__=true, typename std::enable_if<(TickPrivateBool##__LINE__ && __VA_ARGS__), int>::type = 0
+#define TICK_REQUIRES(...)    bool TickPrivateBool ## __LINE__=true, typename std::enable_if<(TickPrivateBool##__LINE__ && __VA_ARGS__), int>::type = 0
+#define TICK_REQUIRES_OC(...) bool TickPrivateBool ## __LINE__,      typename std::enable_if<(TickPrivateBool##__LINE__ && __VA_ARGS__), int>::type
 
-#define TICK_MEMBER_REQUIRES(...) template<TICK_REQUIRES(__VA_ARGS__)>
+#define TICK_MEMBER_REQUIRES(...)    template<TICK_REQUIRES(   __VA_ARGS__)>
+#define TICK_MEMBER_REQUIRES_OC(...) template<TICK_REQUIRES_OC(__VA_ARGS__)>
 
 #define TICK_PARAM_REQUIRES(...) \
 typename std::enable_if< \
@@ -63,4 +65,4 @@ typename std::enable_if< \
     typename tick::detail::private_enum<__LINE__>::type \
 >::type = tick::detail::private_enum<__LINE__>::type::na
 
-#endif
\ No newline at end of file
+#endif