--- src/Makefile.defs.orig	2025-06-06 18:04:30 UTC
+++ src/Makefile.defs
@@ -3,13 +3,13 @@
 
 # directory to install to. Depending on your distribution, you might
 # want to change this to /usr/local
-prefix = /usr
-CC      = gcc
+prefix ?= /usr
+CC      ?= gcc
 
 PAL_VERSION = 0.4.3
 
 # used for portage, rpm, ...
-DESTDIR =
+DESTDIR ?=
 
 # optimizations/warnings
 OPT     = -O2 -Wall
@@ -23,6 +23,6 @@ endif
 DEFS    += -DG_DISABLE_DEPRECATED -DDEBUG
 endif
 
-CFLAGS   = ${OPT} 
-CPPFLAGS = ${INCLDIR} ${DEFS}
-LDFLAGS  = ${LIBDIR} ${LIBS}
+CFLAGS   ?= ${OPT} 
+CPPFLAGS += ${INCLDIR} ${DEFS}
+LDFLAGS  += ${LIBDIR} ${LIBS}