diff --git a/.github/workflows/proof_ci_resources/config.yaml b/.github/workflows/proof_ci_resources/config.yaml
index c87b1ab37..0b4c4c723 100644
--- a/.github/workflows/proof_ci_resources/config.yaml
+++ b/.github/workflows/proof_ci_resources/config.yaml
@@ -1,6 +1,6 @@
 # Use exact versions (instead of "latest") so we're not broken by surprise upgrades.
 cadical-tag: "rel-2.1.0" # tag of latest release: https://github.com/arminbiere/cadical/releases
-cbmc-version: "6.3.1" # semver of latest release: https://github.com/diffblue/cbmc/releases
+cbmc-version: "6.4.0" # semver of latest release: https://github.com/diffblue/cbmc/releases
 cbmc-viewer-version: "3.10" # semver of latest release: https://github.com/model-checking/cbmc-viewer/releases
 kissat-tag: "rel-4.0.1" # tag of latest release: https://github.com/arminbiere/kissat/releases
 litani-version: "1.29.0" # semver of latest release: https://github.com/awslabs/aws-build-accumulator/releases