diff --git a/pr_agent/algo/git_patch_processing.py b/pr_agent/algo/git_patch_processing.py
index 383d488f..5ca4e12b 100644
--- a/pr_agent/algo/git_patch_processing.py
+++ b/pr_agent/algo/git_patch_processing.py
@@ -23,7 +23,10 @@ def extend_patch(original_file_str, patch_str, num_lines) -> str:
         return patch_str
 
     if type(original_file_str) == bytes:
-        original_file_str = original_file_str.decode('utf-8')
+        try:
+            original_file_str = original_file_str.decode('utf-8')
+        except UnicodeDecodeError:
+            return ""
 
     original_lines = original_file_str.splitlines()
     patch_lines = patch_str.splitlines()
diff --git a/pr_agent/algo/pr_processing.py b/pr_agent/algo/pr_processing.py
index 2c5a2957..d02110c7 100644
--- a/pr_agent/algo/pr_processing.py
+++ b/pr_agent/algo/pr_processing.py
@@ -146,6 +146,9 @@ def pr_generate_extended_diff(pr_languages: list,
 
             # extend each patch with extra lines of context
             extended_patch = extend_patch(original_file_content_str, patch, num_lines=patch_extra_lines)
+            if not extend_patch:
+                get_logger().warning(f"Failed to extend patch for file: {file.filename}")
+                continue
             full_extended_patch = f"\n\n## {file.filename}\n\n{extended_patch}\n"
 
             if add_line_numbers_to_hunks:
diff --git a/pr_agent/settings/language_extensions.toml b/pr_agent/settings/language_extensions.toml
index eadb80c8..c13992ec 100644
--- a/pr_agent/settings/language_extensions.toml
+++ b/pr_agent/settings/language_extensions.toml
@@ -44,6 +44,7 @@ default = [
     'ss',
     'svg',
     'tar',
+    'tgz',
     'tsv',
     'ttf',
     'war',