diff --git a/libs/ardour/vst3_module.cc b/libs/ardour/vst3_module.cc
index 7fe7ca2aba..f954d28910 100644
--- a/libs/ardour/vst3_module.cc
+++ b/libs/ardour/vst3_module.cc
@@ -22,6 +22,7 @@
 
 #ifdef __APPLE__
 #include <Carbon/Carbon.h>
+#undef nil
 #elif defined PLATFORM_WINDOWS
 #include <windows.h>
 #include <glibmm.h>
diff --git a/libs/backends/coreaudio/coreaudio_pcmio.h b/libs/backends/coreaudio/coreaudio_pcmio.h
index 65a0b7ee40..84381c8e60 100644
--- a/libs/backends/coreaudio/coreaudio_pcmio.h
+++ b/libs/backends/coreaudio/coreaudio_pcmio.h
@@ -26,6 +26,8 @@
 #include <AudioUnit/AudioUnit.h>
 #include <AudioToolbox/AudioToolbox.h>
 
+#undef nil
+
 #include <map>
 #include <vector>
 #include <string>