diff --git a/.github/workflows/ci_decrypt-oracle.yaml b/.github/workflows/ci_decrypt-oracle.yaml
index d8ecff117..7bced5ebf 100644
--- a/.github/workflows/ci_decrypt-oracle.yaml
+++ b/.github/workflows/ci_decrypt-oracle.yaml
@@ -41,7 +41,7 @@ jobs:
         - uses: actions/checkout@v2
         - uses: actions/setup-python@v1
           with:
-            python-version: 3.x
+            python-version: 3.8
         - run: |
             python -m pip install --upgrade pip
             pip install --upgrade -r ci-requirements.txt
diff --git a/.github/workflows/ci_static-analysis.yaml b/.github/workflows/ci_static-analysis.yaml
index f80c429fe..1b659fa5a 100644
--- a/.github/workflows/ci_static-analysis.yaml
+++ b/.github/workflows/ci_static-analysis.yaml
@@ -30,7 +30,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v1
         with:
-          python-version: 3.x
+          python-version: 3.8
       - run: |
           python -m pip install --upgrade pip
           pip install --upgrade -r ci-requirements.txt
diff --git a/.github/workflows/ci_test-vector-handler.yaml b/.github/workflows/ci_test-vector-handler.yaml
index 570133231..1b24390e4 100644
--- a/.github/workflows/ci_test-vector-handler.yaml
+++ b/.github/workflows/ci_test-vector-handler.yaml
@@ -76,7 +76,7 @@ jobs:
         - uses: actions/checkout@v2
         - uses: actions/setup-python@v1
           with:
-            python-version: 3.x
+            python-version: 3.8
         - run: |
             python -m pip install --upgrade pip
             pip install --upgrade -r ci-requirements.txt
diff --git a/README.rst b/README.rst
index c8cb8340e..f51f61b55 100644
--- a/README.rst
+++ b/README.rst
@@ -39,7 +39,7 @@ Required Prerequisites
 ======================
 
 * Python 2.7+ or 3.4+
-* cryptography >= 1.8.1
+* cryptography >= 2.5.0
 * boto3
 * attrs
 
diff --git a/decrypt_oracle/requirements-actual.txt b/decrypt_oracle/requirements-actual.txt
index 1dd37336b..b1a640978 100644
--- a/decrypt_oracle/requirements-actual.txt
+++ b/decrypt_oracle/requirements-actual.txt
@@ -1,3 +1,3 @@
 # Requirements for actual package
 chalice
-aws-encryption-sdk
+aws-encryption-sdk~=1.7.1
diff --git a/requirements.txt b/requirements.txt
index 7f8f0d532..51badb814 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
 boto3>=1.4.4
-cryptography>=1.8.1
+cryptography>=2.5.0
 attrs>=17.4.0
 wrapt>=1.10.11
diff --git a/test_vector_handlers/requirements.txt b/test_vector_handlers/requirements.txt
index 9de0ee532..8e0b5d514 100644
--- a/test_vector_handlers/requirements.txt
+++ b/test_vector_handlers/requirements.txt
@@ -1,3 +1,3 @@
 attrs >= 17.4.0
-aws-encryption-sdk
+aws-encryption-sdk~=1.7.1
 six