diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bc9dc3d..4736f81 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -34,13 +34,13 @@ jobs:
         include:
           # Linux, gcc
           - toolset: gcc-4.8
-            cxxstd: "11"
+            cxxstd: "11,1y"
             os: ubuntu-latest
             container: ubuntu:18.04
             install:
               - g++-4.8
           - toolset: gcc-4.9
-            cxxstd: "11"
+            cxxstd: "11,14"
             os: ubuntu-latest
             container: ubuntu:16.04
             install: