diff --git a/src/clj/cljs/source_map.clj b/src/clj/cljs/source_map.clj
index 5983c94ac7..9b115dbc52 100644
--- a/src/clj/cljs/source_map.clj
+++ b/src/clj/cljs/source_map.clj
@@ -206,9 +206,10 @@
 ;; Merging
 
 (defn merge-source-maps
-  "Merge an internal source map representation of ClojureScript with
-   an internal source map representation of Google Closure Compiler
-   optimization."
+  "Merge an internal source map representation of a single
+   ClojureScript file with an internal source map representation of
+   the generated JavaScript file that underwent Google Closure
+   Compiler optimization."
   [cljs-map closure-map]
   (loop [line-map-seq (seq cljs-map) new-lines (sorted-map)]
     (if line-map-seq