diff --git a/src/plot.py b/src/plot.py
index 448e46e..0e5ecc6 100644
--- a/src/plot.py
+++ b/src/plot.py
@@ -19,8 +19,8 @@
 from pyfastx import Fastq
 import os
 import pysam
-import bed_annotation
-import plot_utils
+from src import bed_annotation
+from src import plot_utils
 
 # ref_start is always 1based closed
 # ref_end is always 1based closed
@@ -443,7 +443,7 @@ def run(args):
             raise Exception("Error: please provide the alignment file with correct extension")
 
     if use_paf == 0 and use_fasta == 0:
-        print("please provide a .fasta or .fa file when using SAM/BAM")
+        raise Exception("Error: please provide a .fasta or .fa file when using SAM/BAM")
 
     if args.base_limit:
         base_limit = args.base_limit
diff --git a/src/plot_pileup.py b/src/plot_pileup.py
index bbc29f2..a113ae7 100644
--- a/src/plot_pileup.py
+++ b/src/plot_pileup.py
@@ -20,8 +20,8 @@
 import os
 import pysam
 import math
-import bed_annotation
-import plot_utils
+from src import bed_annotation
+from src import plot_utils
 
 # ref_start is always 1based closed
 # ref_end is always 1based closed