diff --git a/Makefile b/Makefile
index 428bcaf..90205a7 100644
--- a/Makefile
+++ b/Makefile
@@ -7,7 +7,7 @@ BIN = skomb
 all: $(BIN)
 
 $(BIN):
-	$(CC) $(CFLAGS) -O2 -DNDEBUG -Funroll-loops -march=native -s $(SRC)/$(BIN).c -o $(BINDIR)/$@
+	$(CC) $(CFLAGS) -O2 -DNDEBUG -funroll-loops -march=native -s $(SRC)/$(BIN).c -o $(BINDIR)/$@
 
 debug:
 	$(CC) $(CFLAGS) -O0 -g $(SRC)/$(BIN).c -o $(BINDIR)/$(BIN)