diff --git a/src/Makefile b/src/Makefile
index 1ecadfd..d2931e8 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1,12 +1,12 @@
-CC=gcc
-.PHONY : all
-
-all: shi7_trimmer gotta_split
-
-clean:
-	rm shi7_trimmer
-	rm gotta_split
-
-shi7_trimmer: shi7_trimmer.c ; $(CC) -m64 -std=gnu99 -O3 -fwhole-program -o shi7_trimmer shi7_trimmer.c
-
-gotta_split: gotta_split_swapped.c ; $(CC) -m64 -std=gnu99 -O3 -o gotta_split gotta_split_swapped.c
+CC=gcc
+.PHONY : all
+
+all: shi7_trimmer gotta_split
+
+clean:
+	rm shi7_trimmer
+	rm gotta_split
+
+shi7_trimmer: shi7_trimmer.c ; $(CC) -m64 -lz -std=gnu99 -O3 -fwhole-program -o shi7_trimmer shi7_trimmer.c
+
+gotta_split: gotta_split_swapped.c ; $(CC) -m64 -std=gnu99 -O3 -o gotta_split gotta_split_swapped.c