diff --git a/examples/twoway/Makefile b/examples/twoway/Makefile
index 4421404c351405e38f91cb21d94d1b23061f76d4..a34e2ea15395118be011d05c164e395d45213888 100644
--- a/examples/twoway/Makefile
+++ b/examples/twoway/Makefile
@@ -2,41 +2,45 @@ UNAME_S=$(shell uname -s)
 
 TARGETS=client server
 LABCOMM_JAR=../../compiler/labcomm2014_compiler.jar
-LABCOMM=java -jar $(LABCOMM_JAR) 
+LABCOMM=java -jar $(LABCOMM_JAR)
+
+#include ../../lib/c/os_compat.mk
 
 CFLAGS=-O3 -g -Wall -Werror -I../../lib/c/2014 -I. -Wno-unused-function
 
 ifeq ($(UNAME_S),Darwin)
-    CFLAGS+=-DLABCOMM_COMPAT=\"labcomm_compat_osx.h\" -DLABCOMM_OS_DARWIN=1  -Wno-tautological-compare
+    CFLAGS+=-DLABCOMM_COMPAT=\"labcomm2014_compat_osx.h\" -DLABCOMM_OS_DARWIN=1
+else
+    CFLAGS+=-Wno-tautological-compare
 endif
 
 all: $(TARGETS:%=gen/%)
 
 test: all
 	LD_LIBRARY_PATH=../../lib/c ./gen/server 2000 &
-	LD_LIBRARY_PATH=../../lib/c ./gen/client localhost 2000 
+	LD_LIBRARY_PATH=../../lib/c ./gen/client localhost 2000
 
 gen/.dir:
 	mkdir -p $@
 
 .PRECIOUS: gen/%.o
 gen/%.o: gen/%.c | gen/.dir
-	$(CC) $(CFLAGS) -c -o $@ $< 
+	$(CC) $(CFLAGS) -c -o $@ $<
 
 gen/%.o: %.c | gen/.dir
-	$(CC) $(CFLAGS) -c -o $@ $< 
+	$(CC) $(CFLAGS) -c -o $@ $<
 
 .PRECIOUS: gen/%.c gen/%.h
 gen/%.c gen/%.h: %.lc | gen/.dir
 	$(LABCOMM) --c=gen/$*.c --h=gen/$*.h $<
 
-gen/client: client.c 
+gen/client: client.c
 	$(CC) -o $@ $(CFLAGS) $^ -lpthread \
 		-L../../lib/c -llabcomm2014
 
-gen/server: server.c 
+gen/server: server.c
 	$(CC) -o $@ $(CFLAGS) $^ -lpthread \
-		-L../../lib/c -llabcomm2014 
+		-L../../lib/c -llabcomm2014
 
 .PHONY: clean distclean
 clean distclean:
@@ -48,7 +52,7 @@ gen/introspecting.o: introspecting.h
 gen/introspecting.o: gen/introspecting_messages.h
 gen/client.o: decimating.h
 gen/client.o: gen/types.h
-gen/client: gen/decimating.o 
+gen/client: gen/decimating.o
 gen/client: gen/decimating_messages.o
 gen/client: gen/introspecting.o
 gen/client: gen/introspecting_messages.o
diff --git a/lib/c/os_compat.mk b/lib/c/os_compat.mk
index b916df333d7ef6023694e44cecbafccb13bd6685..f07be3d87c37d8650cddc19c65e480cd915fdf3f 100644
--- a/lib/c/os_compat.mk
+++ b/lib/c/os_compat.mk
@@ -15,7 +15,7 @@ else ifeq ($(UNAME_S),Darwin)
   CC=$(CROSS_COMPILE)gcc
   LD=$(CROSS_COMPILE)gcc
   CFLAGS=-g -Wall -Werror -O3  -I. -Itest \
-	 -DLABCOMM_COMPAT=\"labcomm_compat_osx.h\" \
+	 -DLABCOMM_COMPAT=\"labcomm$(LIBVERSION)_compat_osx.h\" \
 	 -DLABCOMM_OS_DARWIN=1
 #	 -Wno-tautological-compare -Wno-unused-function
   CFLAGS+=-std=c99