diff --git a/.Rbuildignore b/.Rbuildignore
index f7afbc4..4036990 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -1,12 +1,12 @@
-examples
-rchk
-repo
-revdep
-scripts
-tools
-wiki
-www
-yaml
+examples/
+rchk/
+repo/
+revdep/
+scripts/
+tools/
+wiki/
+www/
+yaml/
 tests/Makefile
 tests/(.+?)\.png$
 tests/(.+?)\.pdf$
diff --git a/.github/workflows/r-cmd-check.yml b/.github/workflows/r-cmd-check.yml
index e9334bd..c1691e6 100644
--- a/.github/workflows/r-cmd-check.yml
+++ b/.github/workflows/r-cmd-check.yml
@@ -24,7 +24,7 @@ jobs:
         config:
           - {os: ubuntu-latest,  r: 'devel', http-user-agent: 'release'}
           - {os: ubuntu-latest,  r: 'release'}
-          - {os: ubuntu-latest,  r: '3.6.0'}
+          - {os: ubuntu-latest,  r: '4.1.0'}
           - {os: macOS-latest,   r: 'release'}
           - {os: windows-latest, r: 'release'}
 
diff --git a/DESCRIPTION b/DESCRIPTION
index 7b3fa76..d31dc7f 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,13 +1,13 @@
 Package: ouch
 Type: Package
 Title: Ornstein-Uhlenbeck Models for Phylogenetic Comparative Hypotheses
-Version: 2.19-4
+Version: 2.20-0
 Date: 2024-07-04
 Authors@R: c(person(given=c("Aaron","A."),family="King",role=c("aut","cre"),email="kingaa@umich.edu",comment=c(ORCID="0000-0001-6159-3207")),
 	person(given=c("Marguerite","A."),family="Butler",role=c("ctb")))
 Maintainer: Aaron A. King <kingaa@umich.edu>
 Description: Fit and compare Ornstein-Uhlenbeck models for evolution along a phylogenetic tree.
-Depends: R(>= 3.6)
+Depends: R(>= 4.1)
 Imports: methods, stats, graphics, grDevices, utils, subplex
 Suggests: ape
 URL: https://kingaa.github.io/ouch/