diff --git a/ql/src/queries/summary/LinesOfCode.ql b/ql/src/queries/summary/LinesOfCode.ql
index 958a931a16d..2b2980d8e17 100644
--- a/ql/src/queries/summary/LinesOfCode.ql
+++ b/ql/src/queries/summary/LinesOfCode.ql
@@ -1,13 +1,14 @@
 /**
  * @id rb/summary/lines-of-code
  * @name Total lines of Ruby code in the database
- * @description The total number of lines of Ruby code across all files,
- *   including vendored code, tests. This query counts the lines of code,
- *   excluding whitespace or comments.
+ * @description The total number of lines of Ruby code from the source code
+ *   directory, including external libraries and auto-generated files. This is a
+ *   useful metric of the size of a database. This query counts the lines of
+ *   code, excluding whitespace or comments.
  * @kind metric
  * @tags summary
  */
 
 import ruby
 
-select sum(File f | | f.getNumberOfLinesOfCode())
+select sum(File f | exists(f.getRelativePath()) | f.getNumberOfLinesOfCode())
diff --git a/ql/src/queries/summary/LinesOfUserCode.ql b/ql/src/queries/summary/LinesOfUserCode.ql
index c7dbb7ee5ba..7f12e3e5a5b 100644
--- a/ql/src/queries/summary/LinesOfUserCode.ql
+++ b/ql/src/queries/summary/LinesOfUserCode.ql
@@ -1,7 +1,9 @@
 /**
  * @id rb/summary/lines-of-user-code
- * @name Lines of authored Ruby code in the database
- * @description The total number of lines of Ruby code across files, excluding library and generated code.
+ * @name Total Lines of user written Ruby code in the database
+ * @description The total number of lines of Ruby code from the source code
+ *   directory, excluding external library and auto-generated files. This
+ *   query counts the lines of code, excluding whitespace or comments.
  * @kind metric
  * @tags summary
  */