diff --git a/configure.ac b/configure.ac
index a14e52de..9cb86142 100644
--- a/configure.ac
+++ b/configure.ac
@@ -27,11 +27,9 @@ AC_PREFIX_DEFAULT(/usr)
 
 dnl Checks for programs.
 
-CFLAGS="$CFLAGS -D_GNU_SOURCE"
-
-
 AC_PROG_CC
 AC_PROG_CPP
+AC_USE_SYSTEM_EXTENSIONS
 AC_PROG_INSTALL
 AC_PROG_LN_S 
 AC_DISABLE_STATIC
diff --git a/src/conf.c b/src/conf.c
index c6a83eef..91fca255 100644
--- a/src/conf.c
+++ b/src/conf.c
@@ -414,12 +414,12 @@ beginning:</P>
 */
 
 
+#include "local.h"
 #include <stdarg.h>
 #include <limits.h>
 #include <sys/stat.h>
 #include <dirent.h>
 #include <locale.h>
-#include "local.h"
 #ifdef HAVE_LIBPTHREAD
 #include <pthread.h>
 #endif
diff --git a/src/timer/timer.c b/src/timer/timer.c
index b71a9f8b..a25e4f79 100644
--- a/src/timer/timer.c
+++ b/src/timer/timer.c
@@ -67,15 +67,10 @@ This example shows opening a timer device and reading of timer events.
  * \anchor example_test_timer
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <sys/ioctl.h>
 #include "timer_local.h"
 
+#include <signal.h>
+
 static int snd_timer_open_conf(snd_timer_t **timer,
 			       const char *name, snd_config_t *timer_root,
 			       snd_config_t *timer_conf, int mode)
diff --git a/src/timer/timer_hw.c b/src/timer/timer_hw.c
index e833fc8c..e61b994d 100644
--- a/src/timer/timer_hw.c
+++ b/src/timer/timer_hw.c
@@ -19,12 +19,6 @@
  *
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
 #include "timer_local.h"
 
 #ifndef PIC
diff --git a/src/timer/timer_local.h b/src/timer/timer_local.h
index 8040b05c..eef3b061 100644
--- a/src/timer/timer_local.h
+++ b/src/timer/timer_local.h
@@ -19,10 +19,9 @@
  *
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <limits.h>
 #include "local.h"
+#include <limits.h>
+#include <sys/ioctl.h>
 
 #ifndef DOC_HIDDEN
 typedef struct {
diff --git a/src/timer/timer_query.c b/src/timer/timer_query.c
index 50b098a8..93d2455d 100644
--- a/src/timer/timer_query.c
+++ b/src/timer/timer_query.c
@@ -26,12 +26,6 @@
  *
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
 #include "timer_local.h"
 
 static int snd_timer_query_open_conf(snd_timer_query_t **timer,
diff --git a/src/timer/timer_query_hw.c b/src/timer/timer_query_hw.c
index 289ca52f..d0c43916 100644
--- a/src/timer/timer_query_hw.c
+++ b/src/timer/timer_query_hw.c
@@ -19,12 +19,6 @@
  *
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
 #include "timer_local.h"
 
 #ifndef PIC
diff --git a/src/ucm/ucm_local.h b/src/ucm/ucm_local.h
index c1655c70..3a5d2c2b 100644
--- a/src/ucm/ucm_local.h
+++ b/src/ucm/ucm_local.h
@@ -36,8 +36,8 @@
 #define UC_MGR_DEBUG
 #endif
 
-#include <pthread.h>
 #include "local.h"
+#include <pthread.h>
 #include "use-case.h"
 
 #define MAX_FILE		256