diff --git a/src/win32_thread.h b/src/win32_thread.h
index 4b5a696f..dd5948f0 100644
--- a/src/win32_thread.h
+++ b/src/win32_thread.h
@@ -25,6 +25,11 @@
 //
 //========================================================================
 
+// This is a workaround for the fact that glfw3.h needs to export APIENTRY (for
+// example to allow applications to correctly declare a GL_KHR_debug callback)
+// but windows.h assumes no one will define APIENTRY before it does
+#undef APIENTRY
+
 #include <windows.h>
 
 #define GLFW_WIN32_TLS_STATE            _GLFWtlsWin32     win32;
diff --git a/src/win32_time.h b/src/win32_time.h
index da5afa41..ef57a5a6 100644
--- a/src/win32_time.h
+++ b/src/win32_time.h
@@ -25,6 +25,11 @@
 //
 //========================================================================
 
+// This is a workaround for the fact that glfw3.h needs to export APIENTRY (for
+// example to allow applications to correctly declare a GL_KHR_debug callback)
+// but windows.h assumes no one will define APIENTRY before it does
+#undef APIENTRY
+
 #include <windows.h>
 
 #define GLFW_WIN32_LIBRARY_TIMER_STATE  _GLFWtimerWin32   win32;