diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 23d83ce03..12584d5bf 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -66,7 +66,7 @@ jobs:
     container: ${{ matrix.container }}
     strategy:
       matrix:
-        container: ['ubuntu:18.04', 'ubuntu:20.04', 'ubuntu:20.10', 'ubuntu:21.04']
+        container: ['ubuntu:18.04', 'ubuntu:20.04', 'ubuntu:21.04', 'ubuntu:21.10']
     env:
       DEBIAN_FRONTEND: noninteractive
       DEBFULLNAME: 'github-actions'
diff --git a/src/crypto/X509CertStore.cpp b/src/crypto/X509CertStore.cpp
index 2d0ab27c7..0a97e91b4 100644
--- a/src/crypto/X509CertStore.cpp
+++ b/src/crypto/X509CertStore.cpp
@@ -197,6 +197,7 @@ int X509CertStore::validate(int ok, X509_STORE_CTX *ctx, const set<string> &type
     switch(X509_STORE_CTX_get_error(ctx))
     {
     case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
+    case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
     case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
     case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
     case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE: