diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 871b12e9..31bad56e 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -16,7 +16,7 @@ env:
 
   # PostgreSQL build from source.
   POSTGRESQL_SOURCE_TAG: 'REL_18_STABLE'
-  OPENSSL_VERSION: '3_3_6'
+  OPENSSL_VERSION: '3_5_5'
   PKGCONFIGLITE_VERSION: '0.28-1'
   WINFLEXBISON_VERSION: '2.5.24'
   WORKFLOW_VERSION_POSTGRESQL: '1' # increment to invalidate cache