diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp
--- a/clang/lib/Driver/ToolChains/Gnu.cpp
+++ b/clang/lib/Driver/ToolChains/Gnu.cpp
@@ -2153,8 +2153,10 @@
       }
     }
 
-    if (ChosenToolsetVersion > 0)
+    if (ChosenToolsetVersion > 0) {
       Prefixes.push_back(ChosenToolsetDir);
+      Prefixes.push_back(ChosenToolsetDir + "/root/usr");
+    }
   }
 
   // Fall back to /usr which is used by most non-Solaris systems.