--- Makefile.am.orig	2023-03-22 03:51:54.000000000 -0500
+++ Makefile.am	2023-03-22 05:56:13.000000000 -0500
@@ -17,7 +17,8 @@
 #
 ABI_VERSION = 10:0:0
 
-AM_CFLAGS=-Wall -D_GNU_SOURCE -I$(srcdir)/libyara/include
+AM_CFLAGS=-Wall
+AM_CPPFLAGS=-I$(srcdir)/libyara/include
 
 #
 # When bison is used in POSIX yacc emulation mode (-y/--yacc option) it