1 files changed, 2 insertions, 0 deletions
diff --git a/filters.c b/filters.c
index 1af5d4a..00e5122 100644
--- a/filters.c
+++ b/filters.c
@@ -16,6 +16,8 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <math.h>
+
 #include "filters.h"