diff --git a/.vscode/settings.json b/.vscode/settings.json
index c156a0c..0f1a7ec 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -70,6 +70,8 @@
     "log.h": "c",
     "buffer_list.h": "c",
     "buffer.h": "c",
-    "stdbool.h": "c"
+    "stdbool.h": "c",
+    "v4l2.h": "c",
+    "stdlib.h": "c"
   }
 }
diff --git a/Makefile b/Makefile
index b2a3fd9..edbc084 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@ SRC := $(wildcard **/*.c **/*/*.c **/*.cc **/*/*.cc)
 HEADERS := $(wildcard **/*.h **/*/*.h **/*.hh **/*/*.hh)
 HTML := $(wildcard html/*.js html/*.html)
 
-CFLAGS := -Werror -Wall -g -I$(CURDIR)
+CFLAGS := -Werror -Wall -g -I$(CURDIR) -D_GNU_SOURCE
 LDLIBS := -lpthread -lstdc++
 
 ifneq (x,x$(shell which ccache))
diff --git a/html/index.html b/html/index.html
index 54ca405..7745dfe 100644
--- a/html/index.html
+++ b/html/index.html
@@ -55,7 +55,7 @@
 			The commands available on some cameras:<br>
 			<br>
 			<ul>
-				<li><a href="option?autofocus">/option?autofocus</a> trigger auto focus.</li>
+				<li><a href="option?AfTrigger=1">/option?AfTrigger=1</a> trigger auto focus.</li>
 			</ul>
 		</li>
 	</ul>
diff --git a/http/http.c b/http/http.c
index d34abaa..fc72fc7 100644
--- a/http/http.c
+++ b/http/http.c
@@ -1,5 +1,3 @@
-#define _GNU_SOURCE
-
 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/opts/log.c b/opts/log.c
index d9c8c92..1d4fba8 100644
--- a/opts/log.c
+++ b/opts/log.c
@@ -1,7 +1,6 @@
 #include "opts/log.h"
 #include "opts/opts.h"
 
-#define _GNU_SOURCE
 #include <string.h>
 
 char *