diff --git a/libstdc++-v3/src/Makefile.am b/libstdc++-v3/src/Makefile.am
index 9c3f4aca655..b83c222d51d 100644
--- a/libstdc++-v3/src/Makefile.am
+++ b/libstdc++-v3/src/Makefile.am
@@ -96,6 +96,16 @@ else
 ldbl_alt128_compat_sources =
 endif
 
+if ENABLE_SYMVERS_GNU_NAMESPACE
+cxx0x_compat_sources =
+else
+cxx0x_compat_sources = \
+	compatibility-atomic-c++0x.cc \
+	compatibility-c++0x.cc \
+	compatibility-chrono.cc \
+	compatibility-condvar.cc \
+	compatibility-thread-c++0x.cc
+endif
 
 parallel_compat_sources = \
 	compatibility-parallel_list.cc  compatibility-parallel_list-2.cc
@@ -108,11 +118,7 @@ cxx98_sources = \
 	${ldbl_compat_sources}
 
 cxx11_sources = \
-	compatibility-c++0x.cc \
-	compatibility-atomic-c++0x.cc \
-	compatibility-thread-c++0x.cc \
-	compatibility-chrono.cc \
-	compatibility-condvar.cc \
+	${cxx0x_compat_sources} \
 	${ldbl_alt128_compat_sources}
 
 libstdc___la_SOURCES = $(cxx98_sources) $(cxx11_sources)
diff --git a/libstdc++-v3/src/Makefile.in b/libstdc++-v3/src/Makefile.in
index 4a06f6cfec1..cef290c5d11 100644
--- a/libstdc++-v3/src/Makefile.in
+++ b/libstdc++-v3/src/Makefile.in
@@ -153,14 +153,17 @@ am__DEPENDENCIES_1 =
 @GLIBCXX_LDBL_COMPAT_TRUE@am__objects_1 = compatibility-ldbl.lo
 am__objects_2 = compatibility.lo compatibility-debug_list.lo \
 	compatibility-debug_list-2.lo $(am__objects_1)
-@ENABLE_DUAL_ABI_TRUE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@am__objects_3 = compatibility-ldbl-alt128-cxx11.lo
-@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@am__objects_4 =  \
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@am__objects_3 = compatibility-atomic-c++0x.lo \
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@	compatibility-c++0x.lo \
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@	compatibility-chrono.lo \
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@	compatibility-condvar.lo \
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@	compatibility-thread-c++0x.lo
+@ENABLE_DUAL_ABI_TRUE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@am__objects_4 = compatibility-ldbl-alt128-cxx11.lo
+@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@am__objects_5 =  \
 @GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	compatibility-ldbl-alt128.lo \
-@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	$(am__objects_3)
-am__objects_5 = compatibility-c++0x.lo compatibility-atomic-c++0x.lo \
-	compatibility-thread-c++0x.lo compatibility-chrono.lo \
-	compatibility-condvar.lo $(am__objects_4)
-am_libstdc___la_OBJECTS = $(am__objects_2) $(am__objects_5)
+@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	$(am__objects_4)
+am__objects_6 = $(am__objects_3) $(am__objects_5)
+am_libstdc___la_OBJECTS = $(am__objects_2) $(am__objects_6)
 libstdc___la_OBJECTS = $(am_libstdc___la_OBJECTS)
 @VTV_CYGMIN_FALSE@am_libstdc___la_rpath = -rpath $(toolexeclibdir)
 @VTV_CYGMIN_TRUE@am_libstdc___la_rpath = -rpath $(toolexeclibdir)
@@ -512,6 +515,14 @@ SUBDIRS = c++98 c++11 c++17 c++20 $(filesystem_dir) $(backtrace_dir)
 @GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	compatibility-ldbl-alt128.cc \
 @GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	${ldbl_alt128_compat_cxx11_sources}
 
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@cxx0x_compat_sources = \
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@	compatibility-atomic-c++0x.cc \
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@	compatibility-c++0x.cc \
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@	compatibility-chrono.cc \
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@	compatibility-condvar.cc \
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@	compatibility-thread-c++0x.cc
+
+@ENABLE_SYMVERS_GNU_NAMESPACE_TRUE@cxx0x_compat_sources = 
 parallel_compat_sources = \
 	compatibility-parallel_list.cc  compatibility-parallel_list-2.cc
 
@@ -522,11 +533,7 @@ cxx98_sources = \
 	${ldbl_compat_sources}
 
 cxx11_sources = \
-	compatibility-c++0x.cc \
-	compatibility-atomic-c++0x.cc \
-	compatibility-thread-c++0x.cc \
-	compatibility-chrono.cc \
-	compatibility-condvar.cc \
+	${cxx0x_compat_sources} \
 	${ldbl_alt128_compat_sources}
 
 libstdc___la_SOURCES = $(cxx98_sources) $(cxx11_sources)
diff --git a/libstdc++-v3/src/c++11/chrono.cc b/libstdc++-v3/src/c++11/chrono.cc
index 6825b5bc4bf..5539d8cbedd 100644
--- a/libstdc++-v3/src/c++11/chrono.cc
+++ b/libstdc++-v3/src/c++11/chrono.cc
@@ -43,8 +43,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   namespace chrono
   {
-    // XXX GLIBCXX_ABI Deprecated
-    inline namespace _V2 {
+_GLIBCXX_BEGIN_INLINE_ABI_NAMESPACE(_V2)
 
     constexpr bool system_clock::is_steady;
 
@@ -94,7 +93,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 #endif
     }
 
-  } // end inline namespace _V2
+_GLIBCXX_END_INLINE_ABI_NAMESPACE(_V2)
   } // namespace chrono
 
 _GLIBCXX_END_NAMESPACE_VERSION
diff --git a/libstdc++-v3/src/c++11/compatibility-c++0x.cc b/libstdc++-v3/src/c++11/compatibility-c++0x.cc
index d48f5bd1e28..768dd666d00 100644
--- a/libstdc++-v3/src/c++11/compatibility-c++0x.cc
+++ b/libstdc++-v3/src/c++11/compatibility-c++0x.cc
@@ -40,6 +40,10 @@
 # error "compatibility-c++0x.cc must be compiled with -std=gnu++0x"
 #endif
 
+#if _GLIBCXX_INLINE_VERSION
+# error "compatibility-thread-c++0x.cc is not needed for gnu-versioned-namespace"
+#endif
+
 #ifdef _GLIBCXX_SHARED
 
 namespace std _GLIBCXX_VISIBILITY(default)
diff --git a/libstdc++-v3/src/c++11/compatibility-chrono.cc b/libstdc++-v3/src/c++11/compatibility-chrono.cc
index 38b96e811fb..6beb8b39a25 100644
--- a/libstdc++-v3/src/c++11/compatibility-chrono.cc
+++ b/libstdc++-v3/src/c++11/compatibility-chrono.cc
@@ -24,6 +24,10 @@
 
 #include <bits/c++config.h>
 
+#if _GLIBCXX_INLINE_VERSION
+# error "compatibility-thread-c++0x.cc is not needed for gnu-versioned-namespace"
+#endif
+
 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
 
 #ifdef _GLIBCXX_USE_GETTIMEOFDAY
diff --git a/libstdc++-v3/src/c++11/compatibility-condvar.cc b/libstdc++-v3/src/c++11/compatibility-condvar.cc
index ea3e11efeda..e3a8b8403ca 100644
--- a/libstdc++-v3/src/c++11/compatibility-condvar.cc
+++ b/libstdc++-v3/src/c++11/compatibility-condvar.cc
@@ -28,6 +28,10 @@
 # error "compatibility-condvar-c++0x.cc must be compiled with -std=gnu++11"
 #endif
 
+#if _GLIBCXX_INLINE_VERSION
+# error "compatibility-thread-c++0x.cc is not needed for gnu-versioned-namespace"
+#endif
+
 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
 
 #define condition_variable_any condition_variable_anyXX
diff --git a/libstdc++-v3/src/c++11/compatibility-thread-c++0x.cc b/libstdc++-v3/src/c++11/compatibility-thread-c++0x.cc
index dbacda2bc44..d920f9f0345 100644
--- a/libstdc++-v3/src/c++11/compatibility-thread-c++0x.cc
+++ b/libstdc++-v3/src/c++11/compatibility-thread-c++0x.cc
@@ -35,6 +35,10 @@
 # error "compatibility-thread-c++0x.cc must be compiled with -std=gnu++0x"
 #endif
 
+#if _GLIBCXX_INLINE_VERSION
+# error "compatibility-thread-c++0x.cc is not needed for gnu-versioned-namespace"
+#endif
+
 #define _GLIBCXX_ASM_SYMVER(cur, old, version) \
    asm (".symver " #cur "," #old "@@@" #version);
 
diff --git a/libstdc++-v3/src/c++11/system_error.cc b/libstdc++-v3/src/c++11/system_error.cc
index 7b1a5a20637..8c13642408d 100644
--- a/libstdc++-v3/src/c++11/system_error.cc
+++ b/libstdc++-v3/src/c++11/system_error.cc
@@ -526,11 +526,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   error_category::~error_category() = default;
 
-  const error_category&
-  _V2::system_category() noexcept { return system_category_instance.obj; }
+_GLIBCXX_BEGIN_INLINE_ABI_NAMESPACE(_V2)
 
   const error_category&
-  _V2::generic_category() noexcept { return generic_category_instance.obj; }
+  system_category() noexcept { return system_category_instance.obj; }
+
+  const error_category&
+  generic_category() noexcept { return generic_category_instance.obj; }
+
+_GLIBCXX_END_INLINE_ABI_NAMESPACE(_V2)
 
   system_error::~system_error() = default;