diff --git a/.github/workflows/matrix-and-codecov-on-merge-to-main.yml b/.github/workflows/matrix-and-codecov-on-merge-to-main.yml
index 3034fdf7..316ae780 100644
--- a/.github/workflows/matrix-and-codecov-on-merge-to-main.yml
+++ b/.github/workflows/matrix-and-codecov-on-merge-to-main.yml
@@ -21,9 +21,9 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest, macos-13, macos-14]
-        python-version: ["3.11", "3.12"]
+        python-version: ["3.11", "3.12", "3.13"]
     env:
-          LATEST_PYTHON_VERSION: "3.12"
+      LATEST_PYTHON_VERSION: "3.13"
     steps:
       - name: Check out diffpy.pdfgui
         uses: actions/checkout@v4
@@ -46,7 +46,7 @@ jobs:
         run: |
           conda install --file requirements/test.txt
           conda install wxpython diffpy.utils matplotlib-base
-          pip install diffpy.pdffit2==1.4.4rc6
+          pip install diffpy.pdffit2==1.5.0rc1
           python -m pip install . --no-deps
 
       - name: Start Xvfb for ubuntu-latest only
diff --git a/.github/workflows/tests-on-pr.yml b/.github/workflows/tests-on-pr.yml
index 09e0c18e..69180175 100644
--- a/.github/workflows/tests-on-pr.yml
+++ b/.github/workflows/tests-on-pr.yml
@@ -25,7 +25,7 @@ jobs:
           auto-update-conda: true
           environment-file: environment.yml
           auto-activate-base: false
-          python-version: 3.12
+          python-version: 3.13
 
       - name: Conda config
         run: >-
@@ -35,8 +35,8 @@ jobs:
       - name: Install diffpy.pdfgui and requirements
         run: |
           conda install --file requirements/test.txt
-          conda install wxpython diffpy.utils matplotlib-base gsl
-          pip install diffpy.pdffit2==1.4.4rc4
+          conda install wxpython diffpy.utils matplotlib-base
+          pip install diffpy.pdffit2==1.5.0rc1
           python -m pip install . --no-deps
 
       - name: Start Xvfb
diff --git a/news/3.13.rst b/news/3.13.rst
new file mode 100644
index 00000000..482e7164
--- /dev/null
+++ b/news/3.13.rst
@@ -0,0 +1,23 @@
+**Added:**
+
+* Added support for python 3.13
+
+**Changed:**
+
+* <news item>
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* <news item>
+
+**Security:**
+
+* <news item>
diff --git a/pyproject.toml b/pyproject.toml
index 796a10af..852f9dec 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,7 +14,7 @@ maintainers = [
 description = "GUI for PDF simulation and structure refinement."
 keywords = ['PDF structure refinement GUI']
 readme = "README.rst"
-requires-python = ">=3.11, <3.13"
+requires-python = ">=3.11, <3.14"
 classifiers = [
         'Development Status :: 5 - Production/Stable',
         'Environment :: Console',
@@ -27,6 +27,7 @@ classifiers = [
         'Operating System :: Unix',
         'Programming Language :: Python :: 3.11',
         'Programming Language :: Python :: 3.12',
+        'Programming Language :: Python :: 3.13',
         'Topic :: Scientific/Engineering :: Physics',
         'Topic :: Scientific/Engineering :: Chemistry',
 ]