diff --git a/makefile b/makefile
index 03a22c6b0..d2c446c4f 100644
--- a/makefile
+++ b/makefile
@@ -129,8 +129,11 @@ CFLAGS_RISCOS_SMALL = $(CFLAGS_RISCOS) -Dsmall
 CFLAGS_NCOS = $(CFLAGS_RISCOS) -Dncos
 CFLAGS_DEBUG = -std=c99 -D_BSD_SOURCE -DDEBUG_BUILD $(WARNFLAGS) -I.. \
 	$(PLATFORM_CFLAGS_DEBUG) -g
-CFLAGS_GTK = -Dnsgtk -std=c99 -D_BSD_SOURCE -Dgtk \
-	$(WARNFLAGS) -I.. -g -O0 -Wformat=2 \
+CFLAGS_GTK = -std=c99 -Dgtk -Dnsgtk \
+	-D_BSD_SOURCE \
+	-DGTK_DISABLE_DEPRECATED \
+	-D_POSIX_C_SOURCE \
+	$(WARNFLAGS) -I.. -g -O2 -fomit-frame-pointer -Wformat=2 \
 	`pkg-config --cflags libglade-2.0 gtk+-2.0` `xml2-config --cflags`
 
 # Stop GCC under Cygwin throwing a fit