diff --git a/workflow/main.nf b/workflow/main.nf
index 1d1d6afd96ab9e1e3285a9e05cdcbf8265e89f12..2736346cdef451c5bb5690b24158f76951c04f91 100644
--- a/workflow/main.nf
+++ b/workflow/main.nf
@@ -61,7 +61,7 @@ process checkDesignFile {
   }
   else {
     """
-    python $baseDir/scripts/check_design.py -d $designFile -f $readsList -a
+    python3 $baseDir/scripts/check_design.py -d $designFile -f $readsList -a
     """
   }
 
diff --git a/workflow/scripts/check_design.py b/workflow/scripts/check_design.py
index 3822e749572715a621332d271c4ea7d80214b1d6..e83c9c613595c3fbd1b2efb9b7baa4cf03771df0 100644
--- a/workflow/scripts/check_design.py
+++ b/workflow/scripts/check_design.py
@@ -158,9 +158,11 @@ def main():
     fastq_df = pd.read_csv(fastq, sep='\t', names=['name', 'path'])
 
     # Check design file
-    check_design_headers(design_df, paired)
+    check_design_headers(design_df, paired, atac)
+
     if not atac:
         check_controls(design_df)
+
     check_replicates(design_df)
     new_design_df = check_files(design_df, fastq_df, paired)