diff --git a/modules/ui/commit.js b/modules/ui/commit.js
index 59cbdaf81..a780a2056 100644
--- a/modules/ui/commit.js
+++ b/modules/ui/commit.js
@@ -123,7 +123,7 @@ export function uiCommit(context) {
                 }
             });
 
-            tags.source = context.cleanTagValue(sources.join(';'));
+            tags.source = context.cleanTagValue(sources.filter(Boolean).join(';'));
         }
 
         context.changeset = new osmChangeset({ tags: tags });