diff --git a/ext/dotnet/dotnet.cpp b/ext/dotnet/dotnet.cpp
index ec9b0e7291a..1fe9db53b2f 100644
--- a/ext/dotnet/dotnet.cpp
+++ b/ext/dotnet/dotnet.cpp
@@ -30,7 +30,7 @@
 
 #ifdef PHP_WIN32
 
-#include <iostream.h>
+#include <iostream>
 #include <math.h>
 #include <comdef.h>
 
diff --git a/ext/rpc/dotnet/dotnet.cpp b/ext/rpc/dotnet/dotnet.cpp
index ec9b0e7291a..1fe9db53b2f 100644
--- a/ext/rpc/dotnet/dotnet.cpp
+++ b/ext/rpc/dotnet/dotnet.cpp
@@ -30,7 +30,7 @@
 
 #ifdef PHP_WIN32
 
-#include <iostream.h>
+#include <iostream>
 #include <math.h>
 #include <comdef.h>