diff --git a/Makefile b/Makefile
index 7e41c97..34c7909 100644
--- a/Makefile
+++ b/Makefile
@@ -73,7 +73,7 @@ USE_SSL?=0
 
 # This is required for test.c only
 ifeq ($(USE_SSL),1)
-  CFLAGS+=-DHIREDIS_TEST_SSL
+  export CFLAGS+=-DHIREDIS_TEST_SSL
 endif
 
 ifeq ($(uname_S),Linux)
@@ -299,12 +299,12 @@ gprof:
 	$(MAKE) CFLAGS="-pg" LDFLAGS="-pg"
 
 gcov:
-	$(MAKE) CFLAGS="-fprofile-arcs -ftest-coverage" LDFLAGS="-fprofile-arcs"
+	$(MAKE) CFLAGS+="-fprofile-arcs -ftest-coverage" LDFLAGS="-fprofile-arcs"
 
 coverage: gcov
 	make check
 	mkdir -p tmp/lcov
-	lcov -d . -c -o tmp/lcov/hiredis.info
+	lcov -d . -c --exclude '/usr*' -o tmp/lcov/hiredis.info
 	genhtml --legend -o tmp/lcov/report tmp/lcov/hiredis.info
 
 noopt: