diff --git a/.github/workflows/R-CMD-check-occasional.yaml b/.github/workflows/R-CMD-check-occasional.yaml
index 7f3dc36d8..0803b2f95 100644
--- a/.github/workflows/R-CMD-check-occasional.yaml
+++ b/.github/workflows/R-CMD-check-occasional.yaml
@@ -1,4 +1,5 @@
 on:
+  push:
   schedule:
    - cron: '17 13 23 * *' # 23rd of month at 13:17 UTC
   workflow_dispatch:
@@ -20,6 +21,8 @@ jobs:
         locale: ['en_US.utf8',
                  # Multibyte characters: Mandarin
                  'zh_CN.utf8',
+                 # Encoding: non-UTF-8 locales for French, Mandarin, and Russian
+                 'fr_CA', 'zh_CN.GB18030', 'ru_RU.KOI8-R', # fr_CA is implicitly 'ISO-8859-1'
                  # Collate order (#3502, see also #7837): Latvian, Azeri, Hungarian, Faroese, Albanian
                  'lv_LV.utf8', 'az_AZ.utf8', 'hu_HU.utf8', 'fo_FO.utf8', 'sq_MK.utf8',
                  # Local time formatting (for R bug #19117)
@@ -31,6 +34,12 @@ jobs:
           # only run non-English locale CI on Ubuntu
           - os: macOS-latest
             locale: 'zh_CN.utf8'
+          - os: macOS-latest
+            locale: 'fr_CA.ISO-8859-1'
+          - os: macOS-latest
+            locale: 'zh_CN.GB18030'
+          - os: macOS-latest
+            locale: 'ru_RU.KOI8-R'
           - os: macOS-latest
             locale: 'lv_LV.utf8'
           - os: macOS-latest
@@ -45,6 +54,12 @@ jobs:
             locale: 'vi_VN.utf8'
           - os: windows-latest
             locale: 'zh_CN.utf8'
+          - os: windows-latest
+            locale: 'fr_CA.ISO-8859-1'
+          - os: windows-latest
+            locale: 'zh_CN.GB18030'
+          - os: windows-latest
+            locale: 'ru_RU.KOI8-R'
           - os: windows-latest
             locale: 'lv_LV.utf8'
           - os: windows-latest
@@ -85,6 +100,21 @@ jobs:
         with:
           r-version: ${{ matrix.r }}
 
+      - name: Override R for locale-specific check
+        if: matrix.os == 'ubuntu-latest' && !contains(matrix.locale, 'utf8')
+        run: |
+          R_BIN_DIR=$(Rscript -e 'cat(R.home("bin"))')
+          for bin in R Rscript; do
+            target="${R_BIN_DIR}/${bin}"
+            sudo mv "$target" "${target}.orig"
+            sudo tee "$target" << EOF
+          #!/bin/bash
+          set -o pipefail
+          exec "${target}.orig" "\$@" 2>&1 | iconv -c -t UTF-8
+          EOF
+            sudo chmod +x "$target"
+          done
+
       - name: Set script permissions
         run: chmod +x configure cleanup 2>/dev/null || true # Silence some GHA Annotations
         shell: bash