diff --git a/.github/workflows/cache.yml b/.github/workflows/cache.yml
index 438912c0..734d5174 100644
--- a/.github/workflows/cache.yml
+++ b/.github/workflows/cache.yml
@@ -14,7 +14,7 @@ jobs:
           auto-update-conda: true
           auto-activate-base: true
           miniconda-version: 'latest'
-          python-version: "3.12"
+          python-version: "3.13"
           environment-file: environment.yml
           activate-environment: quantecon
       - name: Build HTML
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 75a1ee7d..6a7f36e6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,7 +11,7 @@ jobs:
           auto-update-conda: true
           auto-activate-base: true
           miniconda-version: 'latest'
-          python-version: "3.12"
+          python-version: "3.13"
           environment-file: environment.yml
           activate-environment: quantecon
       - name: Install latex dependencies
diff --git a/.github/workflows/execution-linux.yml b/.github/workflows/execution-linux.yml
index fedc2e41..2ae72f73 100644
--- a/.github/workflows/execution-linux.yml
+++ b/.github/workflows/execution-linux.yml
@@ -11,7 +11,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ["ubuntu-latest"]
-        python-version: ["3.12"]
+        python-version: ["3.13"]
     steps:
       - name: Checkout
         uses: actions/checkout@v4
diff --git a/.github/workflows/execution-osx.yml b/.github/workflows/execution-osx.yml
index b6aab55c..b3df8203 100644
--- a/.github/workflows/execution-osx.yml
+++ b/.github/workflows/execution-osx.yml
@@ -11,7 +11,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ["macos-latest"]
-        python-version: ["3.12"]
+        python-version: ["3.13"]
     steps:
       - name: Checkout
         uses: actions/checkout@v4
diff --git a/.github/workflows/execution-win.yml b/.github/workflows/execution-win.yml
index 6f7e1ae3..f0bf9d34 100644
--- a/.github/workflows/execution-win.yml
+++ b/.github/workflows/execution-win.yml
@@ -11,7 +11,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ["windows-latest"]
-        python-version: ["3.12"]
+        python-version: ["3.13"]
     steps:
       - name: Checkout
         uses: actions/checkout@v4
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 58cd14b6..88f354ce 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -16,7 +16,7 @@ jobs:
           auto-update-conda: true
           auto-activate-base: true
           miniconda-version: 'latest'
-          python-version: "3.12"
+          python-version: "3.13"
           environment-file: environment.yml
           activate-environment: quantecon
       - name: Install latex dependencies
diff --git a/environment.yml b/environment.yml
index 11b6e1f7..2c298d46 100644
--- a/environment.yml
+++ b/environment.yml
@@ -2,12 +2,13 @@ name: quantecon
 channels:
   - default
 dependencies:
-  - python=3.12
-  - anaconda=2024.10
+  - python=3.13
+  - anaconda=2025.06
   - pip
   - pip:
+    - sphinx<7 # python=3.13 is missing imgdhr used by epub3 builder and requires sphinx<=6.2
     - jupyter-book==1.0.3
-    - quantecon-book-theme==0.8.2
+    - quantecon-book-theme==0.8.1
     - sphinx-tojupyter==0.3.0
     - sphinxext-rediraffe==0.2.7
     - sphinx-exercise==1.0.1