diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 2d585eba..c2c1baf2 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -24,3 +24,32 @@ jobs:
           ./configure
           make database/database.h
           make -j$(nproc)
+      - name: Build Tcl auto-load modules
+        # These per-module Tcl shared libraries are real products but are not
+        # part of the default target (their modules are not in PROGRAMS), so
+        # build them explicitly to keep them from bit-rotting.
+        run: |
+          for m in lef plot router ext2spice ext2sim; do
+            make -C "$m" tcl-main
+          done
+
+  standard_build_linux:
+    # Non-Tcl "standard" configuration: native magic binary + bundled GNU
+    # readline.  Distinct code paths (MAGIC_WRAPPER off, bundled readline) that
+    # the Tcl build above does not exercise.
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - name: Get Dependencies
+        # X11 + cairo for graphics; ncurses for the bundled readline's configure;
+        # texlive for the docs.  NB: package set not validated on the runner --
+        # adjust if the build cannot find a library.
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libx11-dev libcairo-dev libncurses-dev \
+            texlive-latex-base texlive-latex-recommended texlive-fonts-recommended
+      - name: Build (non-Tcl / standard)
+        run: |
+          ./configure --without-tcl --without-opengl
+          make database/database.h
+          make -j$(nproc)