diff -up email2trac-2.12.2/Makefile.in~ email2trac-2.12.2/Makefile.in
--- email2trac-2.12.2/Makefile.in~	2018-04-26 00:28:32.851177397 +0200
+++ email2trac-2.12.2/Makefile.in	2018-04-26 00:38:06.244860208 +0200
@@ -22,7 +22,7 @@ TRAC_SCRIPT_NAME=email2trac
 
 CC=@CC@
 INSTALL=./install-sh
-CFLAGS=-DMTA_USER=\"$(MTA_USER)\" -DTRAC_USER=\"$(TRAC_USER)\" -DTRAC_SCRIPT_NAME=\"$(TRAC_SCRIPT_NAME)\" -DTRAC_SCRIPT_PATH=\"$(EXEC_PREFIX)\" -DDEBUG=$(DEBUG)
+CFLAGS=-DMTA_USER=\"$(MTA_USER)\" -DTRAC_USER=\"$(TRAC_USER)\" -DTRAC_SCRIPT_NAME=\"$(TRAC_SCRIPT_NAME)\" -DTRAC_SCRIPT_PATH=\"$(EXEC_PREFIX)\" -DDEBUG=$(DEBUG) @CFLAGS@
 
 PYTHON_FILES=delete_spam.py email2trac.py
 WRAPPER_SRC=run_email2trac.c run_email2trac.h