diff --git a/strings/base_stringable_streams.h b/strings/base_stringable_streams.h
index 52b481d6f..fa17b0f3e 100644
--- a/strings/base_stringable_streams.h
+++ b/strings/base_stringable_streams.h
@@ -1,8 +1,11 @@
 
 #ifndef WINRT_LEAN_AND_MEAN
-inline std::wostream& operator<<(std::wostream& stream, winrt::Windows::Foundation::IStringable const& stringable)
+namespace winrt::Windows::Foundation
 {
-    stream << stringable.ToString();
-    return stream;
+    inline std::wostream& operator<<(std::wostream& stream, winrt::Windows::Foundation::IStringable const& stringable)
+    {
+        stream << stringable.ToString();
+        return stream;
+    }
 }
 #endif