diff --git a/libs/pbd/pbd/semaphore.h b/libs/pbd/pbd/semaphore.h
index e54063a15a..81c4057e6a 100644
--- a/libs/pbd/pbd/semaphore.h
+++ b/libs/pbd/pbd/semaphore.h
@@ -22,7 +22,7 @@
 
 #ifdef __APPLE__
 #    include <mach/mach.h>
-#elif defined(_WIN32)
+#elif defined(PLATFORM_WINDOWS)
 #    include <windows.h>
 #else
 #    include <semaphore.h>
diff --git a/libs/pbd/resource.cc b/libs/pbd/resource.cc
index b2988b6314..5ee6f6dc88 100644
--- a/libs/pbd/resource.cc
+++ b/libs/pbd/resource.cc
@@ -17,7 +17,7 @@
 
 */
 
-#ifdef WIN32
+#ifdef PLATFORM_WINDOWS
 #include <stdio.h>
 #else
 #include <sys/time.h>