diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index c8ff9626a31..2a6951f564a 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,3 +1,12 @@
+2017-05-10  H.J. Lu  <hongjiu.lu@intel.com>
+
+	Back port from mainline
+	2017-05-10  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ada/80626
+	* system-linux-x86.ads (Memory_Size): Use Long_Integer'Size
+	instead of Word_Size.
+
 2017-05-02  Release Manager
 
 	* GCC 7.1.0 released.
diff --git a/gcc/ada/system-linux-x86.ads b/gcc/ada/system-linux-x86.ads
index 22a212e265a..533d94efcb5 100644
--- a/gcc/ada/system-linux-x86.ads
+++ b/gcc/ada/system-linux-x86.ads
@@ -70,7 +70,7 @@ package System is
 
    Storage_Unit : constant := 8;
    Word_Size    : constant := Standard'Word_Size;
-   Memory_Size  : constant := 2 ** Word_Size;
+   Memory_Size  : constant := 2 ** Long_Integer'Size;
 
    --  Address comparison