diff --git a/filter/mog.go b/filter/mog.go
index 7cfa8356..99fe332b 100644
--- a/filter/mog.go
+++ b/filter/mog.go
@@ -61,7 +61,7 @@ func NewMOGFilter(dst io.WriteCloser, area, threshold float64, history, kernelSi
 // it using c-go.
 func (m *MOGFilter) Close() error {
 	m.bs.Close()
-	m.kernel.Close()
+	m.knl.Close()
 	for _, window := range m.windows {
 		window.Close()
 	}
@@ -85,12 +85,12 @@ func (m *MOGFilter) Write(f []byte) (int, error) {
 	gocv.Threshold(imgDelta, &imgDelta, 25, 255, gocv.ThresholdBinary)
 
 	// Remove noise.
-	gocv.Erode(imgDelta, &imgDelta, m.kernel)
-	gocv.Dilate(imgDelta, &imgDelta, m.kernel)
+	gocv.Erode(imgDelta, &imgDelta, m.knl)
+	gocv.Dilate(imgDelta, &imgDelta, m.knl)
 
 	// Fill small holes.
-	gocv.Dilate(imgDelta, &imgDelta, m.kernel)
-	gocv.Erode(imgDelta, &imgDelta, m.kernel)
+	gocv.Dilate(imgDelta, &imgDelta, m.knl)
+	gocv.Erode(imgDelta, &imgDelta, m.knl)
 
 	// Find contours and reject ones with a small area.
 	var contours [][]image.Point