diff --git a/requirements.txt b/requirements.txt
index 566f4aff..d940120f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,13 +1,13 @@
 # Base package requirements
-pygeoif
-python-dateutil
+pygeoif==0.7
+python-dateutil==2.7.3
 
 # Testing Requirements
-pytest
-pep8
-coveralls
+pytest==3.8.0
+pep8==1.7.1
+coveralls==1.5.0
 tox>=1.8
 
 # Documentation Requirements
-Sphinx
-sphinx-rtd-theme
+Sphinx==1.8.0
+sphinx-rtd-theme==0.4.1