1 files changed, 4 insertions, 0 deletions
diff --git a/node_modules/clean-css/lib/reader/input-source-map-tracker.js b/node_modules/clean-css/lib/reader/input-source-map-tracker.js
index ea2c03467..4b8730c29 100644
--- a/node_modules/clean-css/lib/reader/input-source-map-tracker.js
+++ b/node_modules/clean-css/lib/reader/input-source-map-tracker.js
@@ -34,6 +34,10 @@ function originalPositionFor(maps, metadata, range, selectorFallbacks) {
     originalPosition = maps[source].originalPositionFor(position);
   }
 
+  if (!originalPosition || originalPosition.column < 0) {
+    return metadata;
+  }
+
   if (originalPosition.line === null && line > 1 && selectorFallbacks > 0) {
     return originalPositionFor(maps, [line - 1, column, source], range, selectorFallbacks - 1);
   }