diff --git a/README.md b/README.md
index b2c1859..7e98c62 100644
--- a/README.md
+++ b/README.md
@@ -21,6 +21,11 @@ One-line install using [pip](https://pypi.python.org/pypi/pip):
 
     pip install ionize
 
+Alternatively, if you're installing from source:
+- Clone the repository, and `cd` into the `ionize` directory.
+- Install the dependencies with `pip3 install -r requirements.txt`
+- Install `ionize` using `python3 setup.py install`
+
 Tutorial
 --------
 Want to use **ionize**? Read the [tutorial][tutorial].
diff --git a/docs/source/conf.py b/docs/source/conf.py
index 9f09c9b..9ea0a4b 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -17,7 +17,7 @@
 
 import sys
 import os
-import mock
+import unittest.mock as mock
 MOCK_MODULES = ['numpy', 'scipy', 'scipy.optimize', 'numpy.linalg', 'Bio',
                 'Bio.SeqUtils', 'Bio.SeqUtils.IsoelectricPoint',
                 'Bio.SeqUtils.ProtParam']
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..f487342
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,7 @@
+pandas>=1.0.1
+pypandoc>=1.4
+numpy>=1.18.1
+scipy>=1.4.1
+Click>=7.0
+biopython>=0.0.6
+simplejson>=3.17.2