diff --git a/requirements.txt b/requirements.txt
index 51d2d8dec1292ff5e78b6c23b3ac8eb9fce6ee53..74cef81cf03607405a970a170cf824295b5ac156 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 pysam==0.15.2
-matplotlib>=3.0
-pandas>=0.24
-numpy>=1.16
-pillow>=5.4
-psutil>=5.6
-scipy>=0.16.1
\ No newline at end of file
+matplotlib==3.1.1
+pandas==0.25.2
+numpy==1.17.3
+pillow==6.2.0
+psutil==5.6.3
+scipy==1.3.1
\ No newline at end of file
diff --git a/singularity/Singularity.1.0 b/singularity/Singularity.1.0
index 2eb0e6f272e5a60aff74454a86c24a80dd1f98bd..7c2f59b5efff506f6eb2e377b7bda26daaadabac 100644
--- a/singularity/Singularity.1.0
+++ b/singularity/Singularity.1.0
@@ -22,6 +22,7 @@ from: ubuntu:bionic
     #################################
     #        installing craw        #
     #################################
+    export PYTHONNOUSERSITE=1
 	pip3 install craw==1.0
 
     #################################
@@ -31,6 +32,13 @@ from: ubuntu:bionic
 	apt-get autoremove -y
     apt-get clean -y
 
+
+%environment
+    # to be reproducible we should nevr search
+    # in python user cache which is the user home
+    # and is mounted automically
+    export PYTHONNOUSERSITE=1
+
 %test
     mkdir /test_craw
     cd /test_craw
@@ -39,6 +47,7 @@ from: ubuntu:bionic
     /usr/bin/python3 craw-1.0.0/tests/run_tests.py -vv
     cd /
     rm -Rf /test_craw
+
 %help
     This singularity image contains the Counter RNAseq Window (CRAW) package.
     Two commands are available \"coverage\" and \"htmp\.