diff --git a/modules/database/create_samples_database.nf b/modules/database/create_samples_database.nf
index 4b1a2e3..a0aa804 100644
--- a/modules/database/create_samples_database.nf
+++ b/modules/database/create_samples_database.nf
@@ -12,7 +12,8 @@ process MERGE_SAMPLES_DATABASE {
 
     script:
     """
-    cat > samples_database_${worksheet}_RNA.csv 
+    echo "sample,worksheet,assay,referral,run,genome_build,sample_reads,ntc_reads" > samples_database_${worksheet}_RNA.csv
+    cat >> samples_database_${worksheet}_RNA.csv
     """
 }