Define default CFLAGS overridable by the environment
diff --git a/Makefile b/Makefile
index ac177dc..f2f079f 100644
--- a/Makefile
+++ b/Makefile
@@ -65,6 +65,9 @@ LIB_MANS := $(patsubst %,man/%,$(LIB_MANS))
LIB_STATIC_OBJS := $(LIB_SRCS:%.c=%.o)
LIB_SHARED_OBJS := $(LIB_SRCS:%.c=%.lo)
+# Set default value for compilation
+CFLAGS ?= -g -Wall -Wextra -Wno-unused-variable
+
MK_CFLAGS := -Iinclude/ -include bsd/bsd.h -D_GNU_SOURCE -D__REENTRANT
prefix := /usr