diff --git a/prepare.sh b/prepare.sh
index 1d9365b..f8fe733 100755
--- a/prepare.sh
+++ b/prepare.sh
@@ -1,4 +1,4 @@
 #!/bin/sh
 
-sudo apt-get install build-essential python-dev python-pip
-pip install -r requirements.txt
\ No newline at end of file
+sudo apt-get install build-essential python-dev python-pip libffi-dev
+pip install -r requirements.txt
diff --git a/requirements.txt b/requirements.txt
index 9fda22d..01dbe0c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,6 +7,6 @@ SQLAlchemy==0.9.8
 passlib==1.6.2
 bcrypt
 six==1.8.0
-itsdangerous
-python-digitalocean
-requests
+itsdangerous==0.24
+python-digitalocean==1.4.2
+requests==2.3.0