diff --git a/main.nf b/main.nf
index d2136a0..18c18e3 100755
--- a/main.nf
+++ b/main.nf
@@ -1261,7 +1261,8 @@ process PFT_Seeding_Mask {
         export ITK_GLOBAL_DEFAULT_NUMBER_OF_THREADS=1
         export OMP_NUM_THREADS=1
         export OPENBLAS_NUM_THREADS=1
-        mrcalc $fa $params.pft_fa_seeding_mask_threshold -ge ${sid}__pft_seeding_mask.nii.gz
+        mrcalc $fa $params.pft_fa_seeding_mask_threshold -ge ${sid}__pft_seeding_mask.nii.gz\
+          -datatype uint8
         """
 }
 
@@ -1328,7 +1329,8 @@ process Local_Tracking_Mask {
         export ITK_GLOBAL_DEFAULT_NUMBER_OF_THREADS=1
         export OMP_NUM_THREADS=1
         export OPENBLAS_NUM_THREADS=1
-        mrcalc $fa $params.local_fa_tracking_mask_threshold -ge ${sid}__local_tracking_mask.nii.gz -datatype uint8
+        mrcalc $fa $params.local_fa_tracking_mask_threshold -ge ${sid}__local_tracking_mask.nii.gz\
+          -datatype uint8
         """
 }