--- a/media/mtransport/third_party/nICEr/src/stun/stun_client_ctx.c
+++ b/media/mtransport/third_party/nICEr/src/stun/stun_client_ctx.c
@@ -30,16 +30,17 @@ THEORY OF LIABILITY, WHETHER IN CONTRACT
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
 
 static char *RCSSTRING __UNUSED__="$Id: stun_client_ctx.c,v 1.2 2008/04/28 18:21:30 ekr Exp $";
 
 #include <assert.h>
 #include <string.h>
+#include <math.h>
 
 #include <nr_api.h>
 #include "stun.h"
 #include "async_timer.h"
 #include "registry.h"
 #include "stun_reg.h"
 #include "nr_crypto.h"
 #include "r_time.h"