diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index e334ff18ebb..13698961910 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,18 @@
+2018-10-11  Jonathan Wakely  <jwakely@redhat.com>
+
+	* include/bits/allocator.h
+	(operator==(const allocator<_Tp>&, const allocator<_Tp>))
+	(operator!=(const allocator<_Tp>&, const allocator<_Tp>)): Replace
+	with inline friends.
+	* include/ext/debug_allocator.h (operator==, operator!=): Replace
+	with inline friend functions that compare to rebound allocators.
+	* include/ext/malloc_allocator.h (operator==, operator!=): Likewise.
+	* include/ext/new_allocator.h (operator==, operator!=): Likewise.
+	* testsuite/ext/debug_allocator/eq.cc: New test.
+	* testsuite/ext/ext_pointer/alloc_eq.cc: New test.
+	* testsuite/ext/malloc_allocator/eq.cc: New test.
+	* testsuite/ext/new_allocator/eq.cc: New test.
+
 2018-10-10  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/87544
diff --git a/libstdc++-v3/include/bits/allocator.h b/libstdc++-v3/include/bits/allocator.h
index c4e3a4b9c15..d9d1d26e13a 100644
--- a/libstdc++-v3/include/bits/allocator.h
+++ b/libstdc++-v3/include/bits/allocator.h
@@ -148,6 +148,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       ~allocator() _GLIBCXX_NOTHROW { }
 
+      friend bool
+      operator==(const allocator&, const allocator&) _GLIBCXX_NOTHROW
+      { return true; }
+
+      friend bool
+      operator!=(const allocator&, const allocator&) _GLIBCXX_NOTHROW
+      { return false; }
+
       // Inherit everything else.
     };
 
@@ -157,24 +165,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     _GLIBCXX_NOTHROW
     { return true; }
 
-  template<typename _Tp>
-    inline bool
-    operator==(const allocator<_Tp>&, const allocator<_Tp>&)
-    _GLIBCXX_NOTHROW
-    { return true; }
-
   template<typename _T1, typename _T2>
     inline bool
     operator!=(const allocator<_T1>&, const allocator<_T2>&)
     _GLIBCXX_NOTHROW
     { return false; }
 
-  template<typename _Tp>
-    inline bool
-    operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
-    _GLIBCXX_NOTHROW
-    { return false; }
-
   // Invalid allocator<cv T> partial specializations.
   // allocator_traits::rebind_alloc can be used to form a valid allocator type.
   template<typename _Tp>
diff --git a/libstdc++-v3/include/ext/debug_allocator.h b/libstdc++-v3/include/ext/debug_allocator.h
index dce224f05ed..3bc750e473b 100644
--- a/libstdc++-v3/include/ext/debug_allocator.h
+++ b/libstdc++-v3/include/ext/debug_allocator.h
@@ -174,16 +174,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       max_size() const throw()
       { return _Traits::max_size(_M_allocator) - _M_extra; }
 
-      friend bool
-      operator==(const debug_allocator& __lhs, const debug_allocator& __rhs)
-      { return __lhs._M_allocator == __rhs._M_allocator; }
-    };
+      template<typename _Alloc2>
+	friend bool
+	operator==(const debug_allocator& __lhs,
+		   const debug_allocator<_Alloc2>& __rhs) _GLIBCXX_NOTHROW
+	{ return __lhs._M_allocator == debug_allocator(__rhs)._M_allocator; }
 
-  template<typename _Alloc>
-    inline bool
-    operator!=(const debug_allocator<_Alloc>& __lhs,
-	       const debug_allocator<_Alloc>& __rhs)
-    { return !(__lhs == __rhs); }
+      template<typename _Alloc2>
+	friend bool
+	operator!=(const debug_allocator& __lhs,
+		   const debug_allocator<_Alloc2>& __rhs) _GLIBCXX_NOTHROW
+	{ return !(__lhs == __rhs); }
+    };
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
diff --git a/libstdc++-v3/include/ext/malloc_allocator.h b/libstdc++-v3/include/ext/malloc_allocator.h
index 8eaf5d44cf7..1ae53b11ddb 100644
--- a/libstdc++-v3/include/ext/malloc_allocator.h
+++ b/libstdc++-v3/include/ext/malloc_allocator.h
@@ -166,17 +166,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       void 
       destroy(pointer __p) { __p->~_Tp(); }
 #endif
-    };
 
-  template<typename _Tp>
-    inline bool
-    operator==(const malloc_allocator<_Tp>&, const malloc_allocator<_Tp>&)
-    { return true; }
-  
-  template<typename _Tp>
-    inline bool
-    operator!=(const malloc_allocator<_Tp>&, const malloc_allocator<_Tp>&)
-    { return false; }
+      template<typename _Up>
+	friend bool
+	operator==(const malloc_allocator&, const malloc_allocator<_Up>&)
+	_GLIBCXX_NOTHROW
+	{ return true; }
+
+      template<typename _Up>
+	friend bool
+	operator!=(const malloc_allocator&, const malloc_allocator<_Up>&)
+	_GLIBCXX_NOTHROW
+	{ return false; }
+    };
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
diff --git a/libstdc++-v3/include/ext/new_allocator.h b/libstdc++-v3/include/ext/new_allocator.h
index 7c50731736b..83c894ce0a7 100644
--- a/libstdc++-v3/include/ext/new_allocator.h
+++ b/libstdc++-v3/include/ext/new_allocator.h
@@ -157,18 +157,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       void
       destroy(pointer __p) { __p->~_Tp(); }
 #endif
+
+      template<typename _Up>
+	friend bool
+	operator==(const new_allocator&, const new_allocator<_Up>&)
+	_GLIBCXX_NOTHROW
+	{ return true; }
+
+      template<typename _Up>
+	friend bool
+	operator!=(const new_allocator&, const new_allocator<_Up>&)
+	_GLIBCXX_NOTHROW
+	{ return false; }
     };
 
-  template<typename _Tp>
-    inline bool
-    operator==(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
-    { return true; }
-
-  template<typename _Tp>
-    inline bool
-    operator!=(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
-    { return false; }
-
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
 
diff --git a/libstdc++-v3/testsuite/ext/debug_allocator/eq.cc b/libstdc++-v3/testsuite/ext/debug_allocator/eq.cc
new file mode 100644
index 00000000000..4623fde384e
--- /dev/null
+++ b/libstdc++-v3/testsuite/ext/debug_allocator/eq.cc
@@ -0,0 +1,31 @@
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-do compile }
+
+#include <ext/debug_allocator.h>
+
+__gnu_cxx::debug_allocator< std::allocator<int> > i;
+__gnu_cxx::debug_allocator< std::allocator<float> > f;
+
+bool b1 = i == i;
+bool b2 = f == f;
+bool b3 = i == f;
+
+bool n1 = i != i;
+bool n2 = f != f;
+bool n3 = i != f;
diff --git a/libstdc++-v3/testsuite/ext/ext_pointer/alloc_eq.cc b/libstdc++-v3/testsuite/ext/ext_pointer/alloc_eq.cc
new file mode 100644
index 00000000000..0b846cd6a1f
--- /dev/null
+++ b/libstdc++-v3/testsuite/ext/ext_pointer/alloc_eq.cc
@@ -0,0 +1,31 @@
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-do compile }
+
+#include <ext/extptr_allocator.h>
+
+__gnu_cxx::_ExtPtr_allocator<int> i;
+__gnu_cxx::_ExtPtr_allocator<float> f;
+
+bool b1 = i == i;
+bool b2 = f == f;
+bool b3 = i == f;
+
+bool n1 = i != i;
+bool n2 = f != f;
+bool n3 = i != f;
diff --git a/libstdc++-v3/testsuite/ext/malloc_allocator/eq.cc b/libstdc++-v3/testsuite/ext/malloc_allocator/eq.cc
new file mode 100644
index 00000000000..12063f1f5eb
--- /dev/null
+++ b/libstdc++-v3/testsuite/ext/malloc_allocator/eq.cc
@@ -0,0 +1,31 @@
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-do compile }
+
+#include <ext/malloc_allocator.h>
+
+__gnu_cxx::malloc_allocator<int> i;
+__gnu_cxx::malloc_allocator<float> f;
+
+bool b1 = i == i;
+bool b2 = f == f;
+bool b3 = i == f;
+
+bool n1 = i != i;
+bool n2 = f != f;
+bool n3 = i != f;
diff --git a/libstdc++-v3/testsuite/ext/new_allocator/eq.cc b/libstdc++-v3/testsuite/ext/new_allocator/eq.cc
new file mode 100644
index 00000000000..6dc60038802
--- /dev/null
+++ b/libstdc++-v3/testsuite/ext/new_allocator/eq.cc
@@ -0,0 +1,31 @@
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-do compile }
+
+#include <ext/new_allocator.h>
+
+__gnu_cxx::new_allocator<int> i;
+__gnu_cxx::new_allocator<float> f;
+
+bool b1 = i == i;
+bool b2 = f == f;
+bool b3 = i == f;
+
+bool n1 = i != i;
+bool n2 = f != f;
+bool n3 = i != f;