diff --git a/.github/workflows/ci_docs.yml b/.github/workflows/ci_docs.yml
index a4d5e4166c1..69aca102a72 100644
--- a/.github/workflows/ci_docs.yml
+++ b/.github/workflows/ci_docs.yml
@@ -68,7 +68,7 @@ jobs:
         run: |
           conda install gmt=6.1.1 numpy pandas xarray netCDF4 packaging \
                         ipython make myst-parser \
-                        sphinx sphinx-copybutton sphinx-gallery sphinx_rtd_theme=0.4.3
+                        sphinx sphinx-copybutton sphinx-gallery sphinx_rtd_theme=0.5.1
 
       # Show installed pkg information for postmortem diagnostic
       - name: List installed packages
diff --git a/environment.yml b/environment.yml
index 6942d6897f0..cc70941f715 100644
--- a/environment.yml
+++ b/environment.yml
@@ -32,4 +32,4 @@ dependencies:
     - sphinx
     - sphinx-copybutton
     - sphinx-gallery
-    - sphinx_rtd_theme=0.4.3
+    - sphinx_rtd_theme=0.5.1