--- netsurf-3.3/Makefile.defaults
+++ netsurf-3.3/Makefile.defaults
@@ -91,12 +91,6 @@
 # Valid options: YES, NO
 NETSURF_FS_BACKING_STORE := NO
 
-# Initial CFLAGS. Optimisation level etc. tend to be target specific.
-CFLAGS :=
-
-# Initial CXXFLAGS. Optimisation level etc. tend to be target specific.
-CXXFLAGS :=
-
 # Default installation/execution prefix
 PREFIX ?= /usr/local
 
--- netsurf-3.3/framebuffer/Makefile.defaults
+++ netsurf-3.3/framebuffer/Makefile.defaults
@@ -2,9 +2,6 @@
 # Framebuffer-target-specific options
 # ----------------------------------------------------------------------------
 
-# Optimisation levels
-CFLAGS += -O2
-
 # Framebuffer default surface provider.
 # Valid values are: x, sdl, linux, vnc, able,
 NETSURF_FB_FRONTEND := sdl
--- netsurf-3.3/framebuffer/Makefile.target
+++ netsurf-3.3/framebuffer/Makefile.target
@@ -42,8 +42,8 @@
 $(eval $(call pkg_config_find_and_add_enabled,MOZJS,mozjs185,JavaScript))
 $(eval $(call pkg_config_find_and_add_enabled,JS,mozilla-js,JavaScript))
 
-CFLAGS += -std=c99 -g -Dsmall \
-	  -D_BSD_SOURCE \
+CFLAGS += -std=c99 -Dsmall \
+	  -D_DEFAULT_SOURCE \
 	  -D_XOPEN_SOURCE=600 \
 	  -D_POSIX_C_SOURCE=200112L \
 	  $(shell $(PKG_CONFIG) --cflags libnsfb libhubbub libcss openssl)
--- netsurf-3.3/gtk/Makefile.defaults
+++ netsurf-3.3/gtk/Makefile.defaults
@@ -26,6 +26,3 @@
 
 # Set default GTK version to build for (2 or 3)
 NETSURF_GTK_MAJOR ?= 2
-
-# Optimisation levels
-CFLAGS += -O2
--- netsurf-3.3/gtk/Makefile.target
+++ netsurf-3.3/gtk/Makefile.target
@@ -46,9 +46,9 @@
 # libsexy currently means we cannot enable this
 #		-DGDK_DISABLE_DEPRECATED 
 
-GTKCFLAGS := -std=c99 -Dgtk -Dnsgtk -g \
+GTKCFLAGS := -std=c99 -Dgtk -Dnsgtk \
 		$(GTKDEPFLAGS) \
-		-D_BSD_SOURCE \
+		-D_BSD_SOURCE -D_DEFAULT_SOURCE \
 		-D_XOPEN_SOURCE=600 \
 		-D_POSIX_C_SOURCE=200809L \
 		-D_NETBSD_SOURCE \
--- netsurf-3.3/test/Makefile
+++ netsurf-3.3/test/Makefile
@@ -1,8 +1,8 @@
-CFLAGS := -std=c99 -g -O0 -D_BSD_SOURCE -D_POSIX_C_SOURCE -I.. \
+CFLAGS := -std=c99 -D_BSD_SOURCE -D_DEFAULT_SOURCE -D_POSIX_C_SOURCE -I.. \
 		$(shell pkg-config --cflags libcurl)
 LDFLAGS := $(shell pkg-config --libs libcurl) -lz
 
-llcache_CFLAGS := $(shell pkg-config --cflags libparserutils libwapcaplet libdom) -O2
+llcache_CFLAGS := $(shell pkg-config --cflags libparserutils libwapcaplet libdom)
 llcache_LDFLAGS := $(shell pkg-config --libs libparserutils libwapcaplet libdom)
 
 llcache_SRCS := content/fetch.c content/fetchers/curl.c \
@@ -19,7 +19,7 @@
 		utils/filename.c utils/nsurl.c utils/corestrings.c \
 		test/urldbtest.c
 
-urldbtest_CFLAGS := $(shell pkg-config --cflags libwapcaplet libdom) -O2
+urldbtest_CFLAGS := $(shell pkg-config --cflags libwapcaplet libdom)
 urldbtest_LDFLAGS := $(shell pkg-config --libs libwapcaplet libdom)
 
 nsurl_SRCS := utils/corestrings.c utils/log.c utils/nsurl.c utils/idna.c utils/utf8proc.c test/nsurl.c