diff --git a/bin/1.1_footprint_extraction/footprints_extraction.py b/bin/1.1_footprint_extraction/footprints_extraction.py
index 47f8075..17345ed 100644
--- a/bin/1.1_footprint_extraction/footprints_extraction.py
+++ b/bin/1.1_footprint_extraction/footprints_extraction.py
@@ -96,6 +96,9 @@ def make_bed_dictionary(bed_file):
 					for i in range(3, len(bed_line_array)):
 						value.append(bed_line_array[i]) 
 
+					if not value: #if there is no bonus information in the original bed file, add a "." to the coulmn in the output bed file
+						value = ["."]
+
 					bed_dictionary[key] = value
 				else: #this is not a bed file, force exit
 					logger.info('Error: please make sure the input bed file has a right format, the problem occured on the line ' + bed_line)