diff --git a/dev-requirements.txt b/dev-requirements.txt
index 9c9fb231..a3fb1d74 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -1,7 +1,7 @@
 # for testing:
 miniboa
 parameterized
-pdfminer
+pdfminer.six
 pyftpdlib
 pyopenssl
 pytest
diff --git a/doc/src/man/linkcheckerrc.rst b/doc/src/man/linkcheckerrc.rst
index 9524aa23..f8011307 100644
--- a/doc/src/man/linkcheckerrc.rst
+++ b/doc/src/man/linkcheckerrc.rst
@@ -525,7 +525,7 @@ daemon must be installed.
 PdfParser
 ^^^^^^^^^
 
-Parse PDF files for URLs to check. Needs the :pypi:`pdfminer` Python package
+Parse PDF files for URLs to check. Needs the :pypi:`pdfminer.six` Python package
 installed.
 
 WordParser
diff --git a/tox.ini b/tox.ini
index 6628e34c..7d1ce15a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,7 +5,7 @@ envlist = py37, py38, py39, py310
 deps =
     pyftpdlib
     parameterized
-    pdfminer
+    pdfminer.six
     pyopenssl
     pytest-xdist
     pytest-cov