diff --git a/doc-requirements.txt b/doc-requirements.txt
index 9d00def..cc24b81 100644
--- a/doc-requirements.txt
+++ b/doc-requirements.txt
@@ -1,4 +1,4 @@
 sphinx>=1.3
 sphinxcontrib-napoleon>=0.4.3
-mock
-sphinx_rtd_theme
+mock==3.0.5
+sphinx_rtd_theme==0.4.3
diff --git a/test-requirements.txt b/test-requirements.txt
index 07d2fbc..822aefe 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1,3 +1,3 @@
-pytest
-pytest-cov
-hypothesis
+pytest==5.2.1
+pytest-cov==2.8.1
+hypothesis==4.41.2