diff --git a/mingw-w64-headers/include/windows.foundation.idl b/mingw-w64-headers/include/windows.foundation.idl
index 875341a..9962df9 100644
--- a/mingw-w64-headers/include/windows.foundation.idl
+++ b/mingw-w64-headers/include/windows.foundation.idl
@@ -4,6 +4,10 @@
  * No warranty is given; refer to the file DISCLAIMER.PD within this package.
  */
 
+#ifdef __WIDL__
+#pragma winrt ns_prefix
+#endif
+
 import "inspectable.idl";
 
 namespace Windows {
diff --git a/mingw-w64-headers/include/windows.security.cryptography.idl b/mingw-w64-headers/include/windows.security.cryptography.idl
index cac6daf..3defa16 100644
--- a/mingw-w64-headers/include/windows.security.cryptography.idl
+++ b/mingw-w64-headers/include/windows.security.cryptography.idl
@@ -4,6 +4,10 @@
  * No warranty is given; refer to the file DISCLAIMER.PD within this package.
  */
 
+#ifdef __WIDL__
+#pragma winrt ns_prefix
+#endif
+
 import "inspectable.idl";
 import "windows.storage.streams.idl";
 
diff --git a/mingw-w64-headers/include/windows.storage.idl b/mingw-w64-headers/include/windows.storage.idl
index 16e7e2b..da41e66 100644
--- a/mingw-w64-headers/include/windows.storage.idl
+++ b/mingw-w64-headers/include/windows.storage.idl
@@ -4,6 +4,10 @@
  * No warranty is given; refer to the file DISCLAIMER.PD within this package.
  */
 
+#ifdef __WIDL__
+#pragma winrt ns_prefix
+#endif
+
 import "inspectable.idl";
 import "hstring.idl";
 import "windows.foundation.idl";
diff --git a/mingw-w64-headers/include/windows.storage.streams.idl b/mingw-w64-headers/include/windows.storage.streams.idl
index 57b706f..5bb0d4a 100644
--- a/mingw-w64-headers/include/windows.storage.streams.idl
+++ b/mingw-w64-headers/include/windows.storage.streams.idl
@@ -4,6 +4,10 @@
  * No warranty is given; refer to the file DISCLAIMER.PD within this package.
  */
 
+#ifdef __WIDL__
+#pragma winrt ns_prefix
+#endif
+
 import "inspectable.idl";
 
 namespace Windows {
diff --git a/mingw-w64-headers/include/windows.system.threading.idl b/mingw-w64-headers/include/windows.system.threading.idl
index 2fafee5..82b12b7 100644
--- a/mingw-w64-headers/include/windows.system.threading.idl
+++ b/mingw-w64-headers/include/windows.system.threading.idl
@@ -4,6 +4,10 @@
  * No warranty is given; refer to the file DISCLAIMER.PD within this package.
  */
 
+#ifdef __WIDL__
+#pragma winrt ns_prefix
+#endif
+
 import "inspectable.idl";
 import "windows.foundation.idl";