diff --git a/sen2chain/cloud_mask.py b/sen2chain/cloud_mask.py
index 3241839ec51b159e2798fa39fbfefab4e5bcf21b..7174a9b84168ed0f82d2877ca7f6bb9c1e3b5b14 100755
--- a/sen2chain/cloud_mask.py
+++ b/sen2chain/cloud_mask.py
@@ -370,21 +370,28 @@ def create_cloud_mask_b11(
     BinaryMorphologicalOperation.ExecuteAndWriteOutput()
 
     # Masquage du masque
-    logger.info("00")
     BandMath = otbApplication.Registry.CreateApplication("BandMath")
-    logger.info("01")
     BandMath.SetParameterStringList("il", [str(cloud_mask),str(out_dilate)])
-    logger.info("02")
     BandMath.SetParameterString("out", out_mask)
     BandMath.SetParameterOutputImagePixelType("out", 0)
-    logger.info("03")
     BandMath.SetParameterString("exp", "(im1b1 == 1) * (im2b1 == 0)")
-    logger.info("04")
     BandMath.ExecuteAndWriteOutput()
-    logger.info("05")
+
+    # Dilatation
+    BinaryMorphologicalOperation = otbApplication.Registry.CreateApplication("BinaryMorphologicalOperation")
+    BinaryMorphologicalOperation.SetParameterString("in", out_mask)
+    BinaryMorphologicalOperation.SetParameterString("out", out_dilate)
+    BinaryMorphologicalOperation.SetParameterOutputImagePixelType("out", 0)
+    BinaryMorphologicalOperation.SetParameterInt("channel", 1)
+    BinaryMorphologicalOperation.SetParameterInt("structype.ball.xradius", dilatation+1)
+    BinaryMorphologicalOperation.SetParameterInt("structype.ball.yradius", dilatation+1)
+    BinaryMorphologicalOperation.SetParameterFloat("filter.dilate.foreval", 1)
+    BinaryMorphologicalOperation.SetParameterString("filter", "dilate")
+    BinaryMorphologicalOperation.ExecuteAndWriteOutput()
+
 
     # Save to JP2000 
-    src_ds = gdal.Open(out_mask)
+    src_ds = gdal.Open(out_dilate)
     driver = gdal.GetDriverByName("JP2OpenJPEG")
     dst_ds = driver.CreateCopy(str(out_path), src_ds,
                                options=["CODEC=JP2", "QUALITY=100", "REVERSIBLE=YES", "YCBCR420=NO"])