diff --git a/requirements.txt b/requirements.txt
index 4a6aff9..3e604c7 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,13 +1,13 @@
-CherryPy==18.1.2
-coverage==4.5.4
-decorator==4.4.0
-fallocate==1.6.4
-nose==1.3.7
-numpy==1.17.0
-progressbar==2.5
-psutil==5.6.3
-python-datetime-tz==0.5.4
-python-dateutil==2.8.0
-requests==2.22.0
-simplejson==3.16.0
-tz==0.2.2
+CherryPy>=18.1.2
+coverage>=4.5.4
+decorator>=4.4.0
+fallocate>=1.6.4
+nose>=1.3.7
+numpy>=1.17.0
+progressbar>=2.5
+psutil>=5.6.3
+python-datetime-tz>=0.5.4
+python-dateutil>=2.8.0
+requests>=2.22.0
+simplejson>=3.16.0
+tz>=0.2.2