diff --git a/ognibuild/buildsystem.py b/ognibuild/buildsystem.py
index 060a304..d34001b 100644
--- a/ognibuild/buildsystem.py
+++ b/ognibuild/buildsystem.py
@@ -1373,10 +1373,11 @@ class Maven(BuildSystem):
         deps_tag = root.find("dependencies")
         if deps_tag:
             for dep in deps_tag.findall("dependency"):
+                version_tag = dep.find("version")
                 yield "core", MavenArtifactRequirement(
                     dep.find("groupId").text,
                     dep.find("artifactId").text,
-                    dep.find("version").text,
+                    version_tag.text if version_tag else None,
                 )
 
 
diff --git a/ognibuild/requirements.py b/ognibuild/requirements.py
index b3650c8..8f29ae6 100644
--- a/ognibuild/requirements.py
+++ b/ognibuild/requirements.py
@@ -213,10 +213,12 @@ class PerlPreDeclaredRequirement(Requirement):
     KNOWN_MODULES = {
         'auto_set_repository': 'Module::Install::Repository',
         'author_tests': 'Module::Install::AuthorTests',
+        'author_requires': 'Module::Install::AuthorRequires',
         'readme_from': 'Module::Install::ReadmeFromPod',
         'catalyst': 'Module::Install::Catalyst',
         'githubmeta': 'Module::Install::GithubMeta',
         'use_ppport': 'Module::Install::XSUtil',
+        'pod_from': 'Module::Install::PodFromEuclid',
         }
 
     def __init__(self, name):