diff --git a/src/event/MultiSocketMonitor.hxx b/src/event/MultiSocketMonitor.hxx
index 7f08c1511..fdf353bcc 100644
--- a/src/event/MultiSocketMonitor.hxx
+++ b/src/event/MultiSocketMonitor.hxx
@@ -31,14 +31,6 @@
 
 #include <assert.h>
 
-#ifdef WIN32
-/* ERROR is a WIN32 macro that poisons our namespace; this is a kludge
-   to allow us to use it anyway */
-#ifdef ERROR
-#undef ERROR
-#endif
-#endif
-
 #ifndef WIN32
 struct pollfd;
 #endif
diff --git a/src/event/PollGroupWinSelect.hxx b/src/event/PollGroupWinSelect.hxx
index 92eec6d13..f60b52ce3 100644
--- a/src/event/PollGroupWinSelect.hxx
+++ b/src/event/PollGroupWinSelect.hxx
@@ -32,6 +32,8 @@
 #include <windows.h>
 #include <winsock2.h>
 
+/* ERROR is a WIN32 macro that poisons our namespace; this is a kludge
+   to allow us to use it anyway */
 #ifdef ERROR
 #undef ERROR
 #endif
diff --git a/src/event/SocketMonitor.hxx b/src/event/SocketMonitor.hxx
index 941bf19c0..d63cab0ab 100644
--- a/src/event/SocketMonitor.hxx
+++ b/src/event/SocketMonitor.hxx
@@ -29,14 +29,6 @@
 #include <assert.h>
 #include <stddef.h>
 
-#ifdef WIN32
-/* ERROR is a WIN32 macro that poisons our namespace; this is a kludge
-   to allow us to use it anyway */
-#ifdef ERROR
-#undef ERROR
-#endif
-#endif
-
 class EventLoop;
 
 /**