diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 2afca6a2c02..0adf5cb7b21 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-05-25  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/79652
+	* g++.dg/cpp0x/pr79652.C: New.
+
 2017-05-25  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/71451
diff --git a/gcc/testsuite/g++.dg/cpp0x/pr79652.C b/gcc/testsuite/g++.dg/cpp0x/pr79652.C
new file mode 100644
index 00000000000..7f86f5ff629
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/pr79652.C
@@ -0,0 +1,12 @@
+// { dg-do compile { target c++11 } }
+
+namespace {
+  struct S {
+    int n;
+  } T;
+  using T = decltype(S :: n);  // { dg-error "redeclared" }
+  namespace {
+    extern int x;
+    extern int x;
+  }
+}