diff --git a/.github/workflows/ci_runner.yml b/.github/workflows/ci_runner.yml
index ff19190..f79155e 100644
--- a/.github/workflows/ci_runner.yml
+++ b/.github/workflows/ci_runner.yml
@@ -21,7 +21,7 @@ jobs:
     ## routine to gather only the changed notebook files and supply them to the matrix
     - name: changed-files
       id: get-changed-files
-      uses: tj-actions/changed-files@v36
+      uses: tj-actions/changed-files@v26.1
       with:
         separator: ","
         files: |
diff --git a/.github/workflows/ci_validation.yml b/.github/workflows/ci_validation.yml
index 095c482..f441cf7 100644
--- a/.github/workflows/ci_validation.yml
+++ b/.github/workflows/ci_validation.yml
@@ -55,7 +55,7 @@ jobs:
       
     - name: Gather changed notebooks
       id: changed-files
-      uses: tj-actions/changed-files@v18.4
+      uses: tj-actions/changed-files@v26.1
       with:
         files: |
           **/*.ipynb
diff --git a/.github/workflows/notebook_pep8check.yml b/.github/workflows/notebook_pep8check.yml
index 64464f3..32a5d09 100644
--- a/.github/workflows/notebook_pep8check.yml
+++ b/.github/workflows/notebook_pep8check.yml
@@ -16,7 +16,7 @@ jobs:
     ## routine to gather only the changed notebook files and supply them to the matrix
     - name: changed-files
       id: get-changed-files
-      uses: tj-actions/changed-files@v35
+      uses: tj-actions/changed-files@v26.1
       with:
         separator: ","
         files: |
diff --git a/.github/workflows/script_pep8check.yml b/.github/workflows/script_pep8check.yml
index bf6e261..38e4347 100644
--- a/.github/workflows/script_pep8check.yml
+++ b/.github/workflows/script_pep8check.yml
@@ -16,7 +16,7 @@ jobs:
     ## routine to gather only the changed python files and supply them to the matrix
     - name: changed-files
       id: get-changed-files
-      uses: tj-actions/changed-files@v35
+      uses: tj-actions/changed-files@v26.1
       with:
         separator: ","
         files: |