diff --git a/.zenodo.json b/.zenodo.json
index 431aca523bf..d3e8a2eb852 100644
--- a/.zenodo.json
+++ b/.zenodo.json
@@ -104,7 +104,7 @@
   "license": "Apache-2.0",
   "related_identifiers": [
     {
-      "identifier": "http://fmriprep.org",
+      "identifier": "https://fmriprep.org",
       "relation": "isPartOf",
       "scheme": "url"
     },
diff --git a/docs/Makefile b/docs/Makefile
index 9ede6066b00..14b7631a5ca 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -11,7 +11,7 @@ PYTHONPATH    = $(PWD)
 
 # User-friendly check for sphinx-build
 ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
-$(error The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed, then set the SPHINXBUILD environment variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don't have Sphinx installed, grab it from http://sphinx-doc.org/)
+$(error The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed, then set the SPHINXBUILD environment variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don't have Sphinx installed, grab it from https://www.sphinx-doc.org/)
 endif
 
 # Internal variables.
diff --git a/docs/conf.py b/docs/conf.py
index 079c66f86b9..a8284a0fa80 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -2,7 +2,7 @@
 #
 # This file does only contain a selection of the most common options. For a
 # full list see the documentation:
-# http://www.sphinx-doc.org/en/master/config
+# https://www.sphinx-doc.org/en/master/usage/configuration.html
 
 # -- Path setup --------------------------------------------------------------
 
diff --git a/docs/links.rst b/docs/links.rst
index 01600c8be01..8d4d562c3d2 100644
--- a/docs/links.rst
+++ b/docs/links.rst
@@ -1,5 +1,5 @@
-.. _Nipype: http://nipype.readthedocs.io/en/latest/
-.. _BIDS: http://bids.neuroimaging.io
+.. _Nipype: https://nipype.readthedocs.io/en/latest/
+.. _BIDS: https://bids.neuroimaging.io
 .. _`BIDS Derivatives`: https://docs.google.com/document/d/17ebopupQxuRwp7U7TFvS6BH03ALJOgGHufxK8ToAvyI
 .. _`BIDS Derivatives RC1`: https://docs.google.com/document/d/17ebopupQxuRwp7U7TFvS6BH03ALJOgGHufxK8ToAvyI
 .. _Installation: installation.html
@@ -16,4 +16,4 @@
 .. _`Docker installation`: https://docs.docker.com/install/
 .. _`Docker Hub`: https://hub.docker.com/r/nipreps/niworkflows/tags
 .. _Singularity: https://github.com/singularityware/singularity
-.. _TACC: https://www.tacc.utexas.edu/
\ No newline at end of file
+.. _TACC: https://www.tacc.utexas.edu/
diff --git a/niworkflows/__about__.py b/niworkflows/__about__.py
index 267a2a25e15..e0923bf4334 100644
--- a/niworkflows/__about__.py
+++ b/niworkflows/__about__.py
@@ -22,8 +22,8 @@
 #
 """
 These pipelines are developed by the Poldrack lab at Stanford University
-(https://nipreps.stanford.edu/) for use at
-the Center for Reproducible Neuroscience (http://reproducibility.stanford.edu/),
+(https://nipreps.stanford.edu/) for use at the
+Center for Reproducible Neuroscience (https://reproducibility.stanford.edu/),
 as well as for open-source software distribution.
 """
 from datetime import datetime
diff --git a/niworkflows/utils/bids.py b/niworkflows/utils/bids.py
index f83c7282414..a552629a628 100644
--- a/niworkflows/utils/bids.py
+++ b/niworkflows/utils/bids.py
@@ -105,8 +105,9 @@ def collect_participants(
     if not all_participants:
         raise BIDSError(
             "Could not find participants. Please make sure the BIDS data "
-            "structure is present and correct. Datasets can be validated online "
-            "using the BIDS Validator (http://bids-standard.github.io/bids-validator/).\n"
+            "structure is present and correct. Datasets can be validated "
+            "online using the BIDS Validator "
+            "(https://bids-standard.github.io/bids-validator/).\n"
             "If you are using Docker for Mac or Docker for Windows, you "
             'may need to adjust your "File sharing" preferences.',
             bids_dir,