diff --git a/src/lib/lib.mak b/src/lib/lib.mak
index 9780aa8c480..fefae3e995c 100644
--- a/src/lib/lib.mak
+++ b/src/lib/lib.mak
@@ -480,6 +480,12 @@ $(LIBOBJ)/portmidi/%.o: $(3RDPARTY)/portmidi/%.c | $(OSPREBUILD)
 	@echo Compiling $<...
 	$(CC) $(CDEFS) $(PMOPTS) $(CCOMFLAGS) $(CONLYFLAGS) -I$(3RDPARTY)/portmidi/pm_common -I$(3RDPARTY)/portmidi/porttime -c $< -o $@
 
+ifeq ($(TARGETOS),macosx)
+$(LIBOBJ)/portmidi/%.o: $(3RDPARTY)/portmidi/%.m | $(OSPREBUILD)
+	@echo Objective-C compiling $<...
+	$(CC) $(CDEFS) $(COBJFLAGS) $(CCOMFLAGS) -c $< -o $@
+endif
+
 #-------------------------------------------------
 # LUA library objects
 #-------------------------------------------------