diff --git a/modules/multiqc/main.nf b/modules/multiqc/main.nf
index 52069c21..6960bd4c 100644
--- a/modules/multiqc/main.nf
+++ b/modules/multiqc/main.nf
@@ -21,7 +21,7 @@ process MULTIQC {
 
     script:
     def args = task.ext.args ?: ''
-    def config = multiqc_config ?: "--config $multiqc_config"
+    def config = multiqc_config ? "--config $multiqc_config" : ''
     """
     multiqc \
         --force \