diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index afe61ddab..8e6992d70 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -18,12 +18,15 @@ jobs:
     - name: module api test
       run: ./runtest-moduleapi --verbose
 
-  build-ubuntu-old:
-    runs-on: ubuntu-16.04
+  build-debian-old:
+    runs-on: ubuntu-latest
+    container: debian:oldoldstable
     steps:
     - uses: actions/checkout@v2
     - name: make
-      run: make
+      run: |
+        apt-get update && apt-get install -y build-essential
+        make
 
   build-macos-latest:
     runs-on: macos-latest
diff --git a/runtest b/runtest
index ade1bd09a..88617c1a6 100755
--- a/runtest
+++ b/runtest
@@ -1,5 +1,5 @@
 #!/bin/sh
-TCL_VERSIONS="8.5 8.6"
+TCL_VERSIONS="8.5 8.6 8.7"
 TCLSH=""
 
 for VERSION in $TCL_VERSIONS; do
diff --git a/runtest-cluster b/runtest-cluster
index 27829a5fe..d46d249d0 100755
--- a/runtest-cluster
+++ b/runtest-cluster
@@ -1,5 +1,5 @@
 #!/bin/sh
-TCL_VERSIONS="8.5 8.6"
+TCL_VERSIONS="8.5 8.6 8.7"
 TCLSH=""
 
 for VERSION in $TCL_VERSIONS; do
diff --git a/runtest-moduleapi b/runtest-moduleapi
index 03b2184ac..d9a06a61c 100755
--- a/runtest-moduleapi
+++ b/runtest-moduleapi
@@ -1,5 +1,5 @@
 #!/bin/sh
-TCL_VERSIONS="8.5 8.6"
+TCL_VERSIONS="8.5 8.6 8.7"
 TCLSH=""
 
 for VERSION in $TCL_VERSIONS; do