diff --git a/programming/language/python3/python3-cryptography/pspec.xml b/programming/language/python3/python3-cryptography/pspec.xml
index 65deb79412..3b2dae0d14 100644
--- a/programming/language/python3/python3-cryptography/pspec.xml
+++ b/programming/language/python3/python3-cryptography/pspec.xml
@@ -22,6 +22,7 @@
             <!-- documentation dependencies -->
             <Dependency>python3-sphinx</Dependency>
             <Dependency>python3-cffi</Dependency>
+            <Dependency>python3-iso8601</Dependency>
             <Dependency>python3-sphinx_rtd_theme</Dependency>
             <Dependency>python3-setuptools-rust</Dependency>
         </BuildDependencies>