diff --git a/.github/workflows/pytest.yml b/.github/workflows/pytest.yml
index b268c95..bb14d24 100644
--- a/.github/workflows/pytest.yml
+++ b/.github/workflows/pytest.yml
@@ -15,7 +15,7 @@ on:
 jobs:
   test:
     runs-on: ubuntu-latest
-    if: github.event_name != 'push' || github.event.pull_request == null
+    if: github.event_name == 'pull_request' || (github.event_name == 'push' && github.ref == 'refs/heads/main')
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
diff --git a/paper/concat_code.sh b/paper/concat_code.sh
index 2503458..abbd676 100755
--- a/paper/concat_code.sh
+++ b/paper/concat_code.sh
@@ -16,10 +16,11 @@ mkdir -p "$(dirname "$OUTPUT_FILE")"
 add_file() {
     local filepath="$1"
     local relpath="${filepath#$PROJECT_ROOT/}"
+    local escaped_path="${relpath//_/\\_}"
 
     # Add section header and code listing (no language-specific highlighting)
-    echo "\\subsection{${relpath}}" >> "$OUTPUT_FILE"
-    echo "\\begin{lstlisting}[caption={${relpath}}]" >> "$OUTPUT_FILE"
+    echo "\\subsection{${escaped_path}}" >> "$OUTPUT_FILE"
+    echo "\\begin{lstlisting}[caption={${escaped_path}}]" >> "$OUTPUT_FILE"
     cat "$filepath" >> "$OUTPUT_FILE"
     echo "" >> "$OUTPUT_FILE"
     echo "\\end{lstlisting}" >> "$OUTPUT_FILE"