fix a typo
diff --git a/Makefile b/Makefile
index 77252de..45df634 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
CC=clang
CFLAGS=-O2 -march=native -mtune=native -flto -Iinclude -g3
-PREFOX?=/usr/local
+PREFIX?=/usr/local
.PHONY: all clean format install cloc
