diff --git a/ql/src/queries/summary/NumberOfFilesExtractedWithErrors.ql b/ql/src/queries/summary/NumberOfFilesExtractedWithErrors.ql
new file mode 100644
index 00000000000..eb871a4086d
--- /dev/null
+++ b/ql/src/queries/summary/NumberOfFilesExtractedWithErrors.ql
@@ -0,0 +1,13 @@
+/**
+ * @id rb/summary/number-of-files-extracted-with-errors
+ * @name Total number of files that were extracted with errors
+ * @description The total number of Ruby code files that we extracted, but where
+ *  at least one extraction error occurred in the process.
+ * @kind metric
+ * @tags summary
+ */
+
+import ruby
+import codeql_ruby.Diagnostics
+
+select count(File f | exists(ExtractionError e | e.getLocation().getFile() = f))