diff --git a/include/boost/unordered/unordered_map_fwd.hpp b/include/boost/unordered/unordered_map_fwd.hpp
index 5e9bb076..edecc5d9 100644
--- a/include/boost/unordered/unordered_map_fwd.hpp
+++ b/include/boost/unordered/unordered_map_fwd.hpp
@@ -24,13 +24,13 @@ namespace boost
         class A = std::allocator<std::pair<const K, T> > >
     class unordered_map;
     template <class K, class T, class H, class P, class A>
-    bool operator==(unordered_map<K, T, H, P, A> const&,
+    inline bool operator==(unordered_map<K, T, H, P, A> const&,
         unordered_map<K, T, H, P, A> const&);
     template <class K, class T, class H, class P, class A>
-    bool operator!=(unordered_map<K, T, H, P, A> const&,
+    inline bool operator!=(unordered_map<K, T, H, P, A> const&,
         unordered_map<K, T, H, P, A> const&);
     template <class K, class T, class H, class P, class A>
-    void swap(unordered_map<K, T, H, P, A>&,
+    inline void swap(unordered_map<K, T, H, P, A>&,
             unordered_map<K, T, H, P, A>&);
 
     template <class K,
@@ -40,13 +40,13 @@ namespace boost
         class A = std::allocator<std::pair<const K, T> > >
     class unordered_multimap;
     template <class K, class T, class H, class P, class A>
-    bool operator==(unordered_multimap<K, T, H, P, A> const&,
+    inline bool operator==(unordered_multimap<K, T, H, P, A> const&,
         unordered_multimap<K, T, H, P, A> const&);
     template <class K, class T, class H, class P, class A>
-    bool operator!=(unordered_multimap<K, T, H, P, A> const&,
+    inline bool operator!=(unordered_multimap<K, T, H, P, A> const&,
         unordered_multimap<K, T, H, P, A> const&);
     template <class K, class T, class H, class P, class A>
-    void swap(unordered_multimap<K, T, H, P, A>&,
+    inline void swap(unordered_multimap<K, T, H, P, A>&,
             unordered_multimap<K, T, H, P, A>&);
 }
 
diff --git a/include/boost/unordered/unordered_set_fwd.hpp b/include/boost/unordered/unordered_set_fwd.hpp
index 8000eb14..fead1243 100644
--- a/include/boost/unordered/unordered_set_fwd.hpp
+++ b/include/boost/unordered/unordered_set_fwd.hpp
@@ -23,13 +23,13 @@ namespace boost
         class A = std::allocator<T> >
     class unordered_set;
     template <class T, class H, class P, class A>
-    bool operator==(unordered_set<T, H, P, A> const&,
+    inline bool operator==(unordered_set<T, H, P, A> const&,
         unordered_set<T, H, P, A> const&);
     template <class T, class H, class P, class A>
-    bool operator!=(unordered_set<T, H, P, A> const&,
+    inline bool operator!=(unordered_set<T, H, P, A> const&,
         unordered_set<T, H, P, A> const&);
     template <class T, class H, class P, class A>
-    void swap(unordered_set<T, H, P, A> &m1,
+    inline void swap(unordered_set<T, H, P, A> &m1,
             unordered_set<T, H, P, A> &m2);
 
     template <class T,
@@ -38,13 +38,13 @@ namespace boost
         class A = std::allocator<T> >
     class unordered_multiset;
     template <class T, class H, class P, class A>
-    bool operator==(unordered_multiset<T, H, P, A> const&,
+    inline bool operator==(unordered_multiset<T, H, P, A> const&,
         unordered_multiset<T, H, P, A> const&);
     template <class T, class H, class P, class A>
-    bool operator!=(unordered_multiset<T, H, P, A> const&,
+    inline bool operator!=(unordered_multiset<T, H, P, A> const&,
         unordered_multiset<T, H, P, A> const&);
     template <class T, class H, class P, class A>
-    void swap(unordered_multiset<T, H, P, A> &m1,
+    inline void swap(unordered_multiset<T, H, P, A> &m1,
             unordered_multiset<T, H, P, A> &m2);
 }