diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 06ac725..5920521 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -43,9 +43,13 @@ jobs:
     - name: Get changed files
       id: getfile
       run: |
-        files=$(git diff-tree --no-commit-id --name-only -r $(git log -n 1 --pretty=format:"%H") | grep ".ttl$")
+        files=$(git diff-tree --no-commit-id --name-only -r $(git log -n 1 --pretty=format:"%H") | grep ".ttl$" || echo "")
+        if [ -z "$files" ]; then
+          echo "No .ttl files changed."
+          exit 0
+        fi
         echo "::set-output name=files::$files"
-    
+      
     - name: Run Python script on changed files
       run: |
         IFS=' ' read -ra ADDR <<< "${{ steps.getfile.outputs.files }}"
@@ -60,7 +64,12 @@ jobs:
             
     - name: Commit and Push changes
       run: |
-         git add -u  # Adds only modified files to the staging area
-         git commit -m "Updated .ttl files with base URI [AUTO]"
-         git push    
+        git add -u  # Adds only modified files to the staging area
+        if git diff-index --quiet HEAD --; then
+          echo "No changes to commit"
+        else
+          git commit -m "Updated .ttl files with base URI [AUTO]"
+          git push
+        fi
+      
 
diff --git a/add-base.py b/add-base.py
index e9c38c3..ad29e16 100644
--- a/add-base.py
+++ b/add-base.py
@@ -18,9 +18,16 @@ def add_base_if_missing(file_path):
     with open(file_path, 'r') as f:
         lines = f.readlines()
 
-    # Insert the @base declaration before line #4
-    if "@base" not in lines[3]:  # Checking to ensure it's not already added
-        lines.insert(3, f"@base <{base_uri}> .\n")
+    # Find the line number of the first occurrence of '@prefix'
+    prefix_line_number = next((i for i, line in enumerate(lines) if line.startswith("@prefix")), None)
+
+    if prefix_line_number is not None:
+        # Check if @base is already in the file before the first @prefix
+        if all("@base" not in line for line in lines[:prefix_line_number]):
+            lines.insert(prefix_line_number, f"@base <{base_uri}> .\n")
+    else:
+        # If no @prefix is found, just append at the end (or handle in some other manner)
+        lines.append(f"@base <{base_uri}> .\n")
 
     with open(file_path, 'w') as f:
         f.writelines(lines)
diff --git a/file1.shapes.ttl b/file1.shapes.ttl
index 7119ebc..d7f9c7e 100644
--- a/file1.shapes.ttl
+++ b/file1.shapes.ttl
@@ -2,6 +2,7 @@
 # imports: http://datashapes.org/dash
 # prefix: file1
 
+@base <https://example/file1> .
 @prefix dash: <http://datashapes.org/dash#> .
 @prefix file1: <https://example/file1#> .
 @prefix owl: <http://www.w3.org/2002/07/owl#> .
@@ -13,7 +14,7 @@
 <https://example/file1>
   a owl:Ontology ;
   owl:imports <http://datashapes.org/dash> ;
-  owl:versionInfo "Created with     TopBraid Composer" ;
+  owl:versionInfo "Created with           TopBraid Composer" ;
 .
 file1:DestinationClass_1
   a file1:Location ;