diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8ebe1f3..9a6bece 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -187,7 +187,7 @@ jobs:
   bazel-ubuntu:
     name: bazel ubuntu amd64
     runs-on: ubuntu-latest
-    container: ubuntu:24.04
+    container: ubuntu:26.04
     steps:
       - name: setup
         run: |
@@ -220,7 +220,7 @@ jobs:
   bazel-ubuntu-arm64:
     name: bazel ubuntu arm64
     runs-on: ubuntu-24.04-arm
-    container: ubuntu:24.04
+    container: ubuntu:26.04
     steps:
       - name: setup
         run: |
@@ -476,7 +476,7 @@ jobs:
   cmake-ubuntu:
     name: cmake ubuntu amd64
     runs-on: ubuntu-latest
-    container: ubuntu:24.04
+    container: ubuntu:26.04
     steps:
       - name: setup
         run: |
@@ -521,7 +521,7 @@ jobs:
   cmake-ubuntu-arm64:
     name: cmake ubuntu arm64
     runs-on: ubuntu-24.04-arm
-    container: ubuntu:24.04
+    container: ubuntu:26.04
     steps:
       - name: setup
         run: |
@@ -768,7 +768,7 @@ jobs:
   gradle-ubuntu:
     name: gradle ubuntu amd64
     runs-on: ubuntu-latest
-    container: ubuntu:24.04
+    container: ubuntu:26.04
     steps:
       - name: setup
         run: |
@@ -803,7 +803,7 @@ jobs:
   gradle-ubuntu-arm64:
     name: gradle ubuntu arm64
     runs-on: ubuntu-24.04-arm
-    container: ubuntu:24.04
+    container: ubuntu:26.04
     steps:
       - name: setup
         run: |
diff --git a/Dockerfile b/Dockerfile
index 6e786d0..5e30c8c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -33,7 +33,7 @@
 # <https://gamma.cs.unc.edu/RVO2/>
 #
 
-FROM ubuntu:24.04
+FROM ubuntu:26.04
 ARG TARGETARCH
 LABEL org.opencontainers.image.authors="Jur van den Berg, Stephen J. Guy, Jamie Snape, Ming C. Lin, Dinesh Manocha"
 LABEL org.opencontainers.image.base.name="docker.io/library/ubuntu:24.04"