diff --git a/.github/workflows/avail.yml b/.github/workflows/avail.yml
index ae2f0aa..2a1bd4a 100644
--- a/.github/workflows/avail.yml
+++ b/.github/workflows/avail.yml
@@ -28,7 +28,7 @@ jobs:
       fail-fast: false
       matrix:
         debian-versions: [bookworm]
-        rust-versions: [1.79.0]
+        rust-versions: [1.78.0]
         clang-versions: [17]
         rustc-targets: ["x86-64-v2", "x86-64-v3"]
     steps: