diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index d186abb9..e1d91692 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -71,9 +71,8 @@ jobs:
           # smoketests for different toolchains
           - {toolchain: stable, os: windows-latest, experimental: false, flags: ""}
           - {toolchain: stable, os: macos-latest, experimental: false, flags: ""}
-          # data structure size changes - wait for beta to become stable and uncomment
-          #- {toolchain: beta, os: ubuntu-latest, experimental: false, flags: ""}
-          #- {toolchain: nightly, os: ubuntu-latest, experimental: true, flags: ""}
+          - {toolchain: beta, os: ubuntu-latest, experimental: false, flags: ""}
+          - {toolchain: nightly, os: ubuntu-latest, experimental: true, flags: ""}
       fail-fast: false
     steps:
     - name: Checkout