diff --git a/configure.ac b/configure.ac
index 532671adb5..e1fe0765c3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -167,6 +167,11 @@ dnl *** checks for compiler characteristics ***
 dnl *** checks for library functions ***
 AC_CHECK_FUNCS([gmtime_r])
 
+LIBS_SAVE=$LIBS
+LIBS="$LIBS $LIBM"
+AC_CHECK_FUNCS([log2])
+LIBS=$LIBS_SAVE
+
 dnl *** checks for headers ***
 AC_CHECK_HEADERS([sys/utsname.h])
 
diff --git a/sys/vdpau/h264/gsth264parser.c b/sys/vdpau/h264/gsth264parser.c
index 861bab2443..659498226c 100644
--- a/sys/vdpau/h264/gsth264parser.c
+++ b/sys/vdpau/h264/gsth264parser.c
@@ -18,9 +18,17 @@
  * Boston, MA 02111-1307, USA.
  */
 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
 #include <string.h>
 #include <math.h>
 
+#ifndef HAVE_LOG2
+#define log2(x) (log(x)/log(2))
+#endif
+
 #include "gstnalreader.h"
 
 #include "gsth264parser.h"