diff --git a/src/libBigWig/Makefile b/src/libBigWig/Makefile
index 405673b..fda5366 100644
--- a/src/libBigWig/Makefile
+++ b/src/libBigWig/Makefile
@@ -1,4 +1,4 @@
-CFLAGS = -fPIC -DNOCURL
+CFLAGS = -Wall -O3 -Wsign-compare -DNOCURL  -fpic
 
 BIGWIG_OBJECTS = bwRead.o bwStats.o bwValues.o bwWrite.o io.o