--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
 
 build ?= release
 
-prefix ?= /usr/local
+prefix ?= /usr
 bindir ?= $(prefix)/bin
 incdir ?= $(prefix)/include
 libdir ?= $(prefix)/lib
@@ -11,7 +11,7 @@
 
 # Compiler flags for various configurations:
 
-CFLAGS := -std=c99 -pedantic -Wall -Wextra -Wno-unused-parameter
+CFLAGS += -std=c99 -pedantic -Wall -Wextra -Wno-unused-parameter
 
 ifeq "$(CC)" "clang"
 CFLAGS += -Wunreachable-code
@@ -22,16 +22,6 @@
 LDFLAGS += -Wl,--gc-sections
 endif
 
-ifeq "$(build)" "debug"
-CFLAGS += -g
-else ifeq "$(build)" "sanitize"
-CFLAGS += -pipe -g -fsanitize=address -fno-omit-frame-pointer
-LDFLAGS += -fsanitize=address
-else
-CFLAGS += -Os
-LDFLAGS += -Wl,-s
-endif
-
 # You shouldn't need to edit anything below here.
 
 OUT := build/$(build)