diff --git a/.gitea/workflows/tests.yml b/.gitea/workflows/tests.yml
index bda7ce86..c353b82c 100644
--- a/.gitea/workflows/tests.yml
+++ b/.gitea/workflows/tests.yml
@@ -76,6 +76,12 @@ jobs:
         uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86  # v5
         with:
           version: "0.11.11"
+          # act_runner shares /tmp across jobs; the uv wheel cache
+          # (default /tmp/setup-uv-cache) fills the partition and
+          # breaks subsequent runs with "No space left on device".
+          # Caching is useless on ephemeral runners anyway — the
+          # cache directory is discarded when the container exits.
+          enable-cache: false
 
       - name: Set up Python 3.11
         if: steps.changes.outputs.run == 'true'
@@ -156,6 +162,12 @@ jobs:
         uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86  # v5
         with:
           version: "0.11.11"
+          # act_runner shares /tmp across jobs; the uv wheel cache
+          # (default /tmp/setup-uv-cache) fills the partition and
+          # breaks subsequent runs with "No space left on device".
+          # Caching is useless on ephemeral runners anyway — the
+          # cache directory is discarded when the container exits.
+          enable-cache: false
 
       - name: Set up Python 3.11
         if: steps.changes.outputs.run == 'true'