diff --git a/.github/workflows/diagnose-final-agent-validation.yml b/.github/workflows/diagnose-final-agent-validation.yml
index 8b8ded79..5582a654 100644
--- a/.github/workflows/diagnose-final-agent-validation.yml
+++ b/.github/workflows/diagnose-final-agent-validation.yml
@@ -12,7 +12,7 @@ permissions:
 
 jobs:
   diagnose:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     timeout-minutes: 45
     steps:
       - uses: actions/checkout@v7
diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 5f927811..78c02ba4 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -49,7 +49,7 @@ jobs:
 
   agent-validation:
     name: Agent validation (deterministic)
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     timeout-minutes: 45
     steps:
       - name: Checkout sources
@@ -76,7 +76,7 @@ jobs:
 
   agent-fuzz:
     name: Agent protocol fuzz smoke
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     timeout-minutes: 15
     steps:
       - name: Checkout sources