--- a/Makefile.in
+++ b/Makefile.in
@@ -233,7 +233,7 @@ AUTOMAKE = @AUTOMAKE@
 AWK = @AWK@
 CC = @CC@
 CCDEPMODE = @CCDEPMODE@
-CFLAGS = -O2 -fno-builtin -Wall -DSBINDIR='"$(sbindir)"'
+CFLAGS = $(COPTS) -fno-builtin -Wall -DSBINDIR='"$(sbindir)"'
 CPP = @CPP@
 CPPFLAGS = @CPPFLAGS@
 CSCOPE = @CSCOPE@