diff --git .github/workflows/linux-build.yml .github/workflows/linux-build.yml
index 43c80e83aa..9031541931 100644
--- .github/workflows/linux-build.yml
+++ .github/workflows/linux-build.yml
@@ -23,6 +23,8 @@ jobs:
           - "CFLAGS=-ftrapv"
           - "CPPFLAGS=-DTCL_UTF_MAX=4"
           - "CPPFLAGS=-DTCL_UTF_MAX=6"
+          # Duplicated below
+          - "--disable-64bit CPPFLAGS=-m32 CFLAGS=-m32 LDFLAGS=-m32"
     defaults:
       run:
         shell: bash
@@ -30,6 +32,11 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+      - name: Install 32-bit dependencies if needed
+        # Duplicated from above
+        if: ${{ matrix.cfgopt == '--disable-64bit CPPFLAGS=-m32 CFLAGS=-m32 LDFLAGS=-m32' }}
+        run: |
+          sudo apt install gcc-multilib libc6-dev-i386
       - name: Prepare
         run: |
           touch tclStubInit.c tclOOStubInit.c
