diff --git a/tools/hscollider/main.cpp b/tools/hscollider/main.cpp
index b289135b..e1e543cc 100644
--- a/tools/hscollider/main.cpp
+++ b/tools/hscollider/main.cpp
@@ -1824,11 +1824,11 @@ unique_ptr<CorporaSource> buildCorpora(const vector<string> &corporaFiles,
                 exit_with_fail();
             }
         }
-        return c;
+        return move(c); /* move allows unique_ptr<CorporaSource> conversion */
     } else {
         auto c = ue2::make_unique<NfaGeneratedCorpora>(
             exprMap, corpus_gen_prop, force_utf8, force_prefilter);
-        return c;
+        return move(c);
     }
 }