diff --git a/cpp/ql/src/Critical/DoubleFree.ql b/cpp/ql/src/Critical/DoubleFree.ql
index 802c81fd050b..a454b63d5a5e 100644
--- a/cpp/ql/src/Critical/DoubleFree.ql
+++ b/cpp/ql/src/Critical/DoubleFree.ql
@@ -37,6 +37,5 @@ where
   DoubleFree::flowPath(source, sink) and
   isFree(source.getNode(), _, _, dealloc) and
   isFree(sink.getNode(), e2)
-select sink.getNode(), source, sink,
-  "Memory pointed to by '" + e2.toString() + "' may already have been freed by $@.", dealloc,
-  dealloc.toString()
+select sink.getNode(), source, sink, "Memory pointed to by $@ may already have been freed by $@.",
+  e2, e2.toString(), dealloc, dealloc.toString()
diff --git a/cpp/ql/test/query-tests/Critical/MemoryFreed/DoubleFree.expected b/cpp/ql/test/query-tests/Critical/MemoryFreed/DoubleFree.expected
index bd8868102842..893f1c7e79ac 100644
--- a/cpp/ql/test/query-tests/Critical/MemoryFreed/DoubleFree.expected
+++ b/cpp/ql/test/query-tests/Critical/MemoryFreed/DoubleFree.expected
@@ -41,16 +41,16 @@ nodes
 | test_free.cpp:302:12:302:14 | buf | semmle.label | buf |
 subpaths
 #select
-| test_free.cpp:14:10:14:10 | a | test_free.cpp:11:10:11:10 | pointer to free output argument | test_free.cpp:14:10:14:10 | a | Memory pointed to by 'a' may already have been freed by $@. | test_free.cpp:11:5:11:8 | call to free | call to free |
-| test_free.cpp:31:27:31:27 | a | test_free.cpp:30:10:30:10 | pointer to free output argument | test_free.cpp:31:27:31:27 | a | Memory pointed to by 'a' may already have been freed by $@. | test_free.cpp:30:5:30:8 | call to free | call to free |
-| test_free.cpp:37:27:37:27 | a | test_free.cpp:35:10:35:10 | pointer to free output argument | test_free.cpp:37:27:37:27 | a | Memory pointed to by 'a' may already have been freed by $@. | test_free.cpp:35:5:35:8 | call to free | call to free |
-| test_free.cpp:46:10:46:10 | a | test_free.cpp:42:27:42:27 | pointer to free output argument | test_free.cpp:46:10:46:10 | a | Memory pointed to by 'a' may already have been freed by $@. | test_free.cpp:42:22:42:25 | call to free | call to free |
-| test_free.cpp:46:10:46:10 | a | test_free.cpp:44:27:44:27 | pointer to free output argument | test_free.cpp:46:10:46:10 | a | Memory pointed to by 'a' may already have been freed by $@. | test_free.cpp:44:22:44:25 | call to free | call to free |
-| test_free.cpp:51:10:51:10 | a | test_free.cpp:50:27:50:27 | pointer to free output argument | test_free.cpp:51:10:51:10 | a | Memory pointed to by 'a' may already have been freed by $@. | test_free.cpp:50:22:50:25 | call to free | call to free |
-| test_free.cpp:72:14:72:14 | a | test_free.cpp:69:10:69:10 | pointer to free output argument | test_free.cpp:72:14:72:14 | a | Memory pointed to by 'a' may already have been freed by $@. | test_free.cpp:69:5:69:8 | call to free | call to free |
-| test_free.cpp:85:12:85:12 | a | test_free.cpp:83:12:83:12 | pointer to operator delete output argument | test_free.cpp:85:12:85:12 | a | Memory pointed to by 'a' may already have been freed by $@. | test_free.cpp:83:5:83:13 | delete | delete |
-| test_free.cpp:103:10:103:10 | a | test_free.cpp:101:10:101:10 | pointer to free output argument | test_free.cpp:103:10:103:10 | a | Memory pointed to by 'a' may already have been freed by $@. | test_free.cpp:101:5:101:8 | call to free | call to free |
-| test_free.cpp:129:10:129:11 | * ... | test_free.cpp:128:10:128:11 | pointer to free output argument | test_free.cpp:129:10:129:11 | * ... | Memory pointed to by '* ...' may already have been freed by $@. | test_free.cpp:128:5:128:8 | call to free | call to free |
-| test_free.cpp:154:10:154:10 | a | test_free.cpp:152:27:152:27 | pointer to free output argument | test_free.cpp:154:10:154:10 | a | Memory pointed to by 'a' may already have been freed by $@. | test_free.cpp:152:22:152:25 | call to free | call to free |
-| test_free.cpp:209:10:209:10 | a | test_free.cpp:207:10:207:10 | pointer to free output argument | test_free.cpp:209:10:209:10 | a | Memory pointed to by 'a' may already have been freed by $@. | test_free.cpp:207:5:207:8 | call to free | call to free |
-| test_free.cpp:302:12:302:14 | buf | test_free.cpp:301:12:301:14 | pointer to g_free output argument | test_free.cpp:302:12:302:14 | buf | Memory pointed to by 'buf' may already have been freed by $@. | test_free.cpp:301:5:301:10 | call to g_free | call to g_free |
+| test_free.cpp:14:10:14:10 | a | test_free.cpp:11:10:11:10 | pointer to free output argument | test_free.cpp:14:10:14:10 | a | Memory pointed to by $@ may already have been freed by $@. | test_free.cpp:14:10:14:10 | a | a | test_free.cpp:11:5:11:8 | call to free | call to free |
+| test_free.cpp:31:27:31:27 | a | test_free.cpp:30:10:30:10 | pointer to free output argument | test_free.cpp:31:27:31:27 | a | Memory pointed to by $@ may already have been freed by $@. | test_free.cpp:31:27:31:27 | a | a | test_free.cpp:30:5:30:8 | call to free | call to free |
+| test_free.cpp:37:27:37:27 | a | test_free.cpp:35:10:35:10 | pointer to free output argument | test_free.cpp:37:27:37:27 | a | Memory pointed to by $@ may already have been freed by $@. | test_free.cpp:37:27:37:27 | a | a | test_free.cpp:35:5:35:8 | call to free | call to free |
+| test_free.cpp:46:10:46:10 | a | test_free.cpp:42:27:42:27 | pointer to free output argument | test_free.cpp:46:10:46:10 | a | Memory pointed to by $@ may already have been freed by $@. | test_free.cpp:46:10:46:10 | a | a | test_free.cpp:42:22:42:25 | call to free | call to free |
+| test_free.cpp:46:10:46:10 | a | test_free.cpp:44:27:44:27 | pointer to free output argument | test_free.cpp:46:10:46:10 | a | Memory pointed to by $@ may already have been freed by $@. | test_free.cpp:46:10:46:10 | a | a | test_free.cpp:44:22:44:25 | call to free | call to free |
+| test_free.cpp:51:10:51:10 | a | test_free.cpp:50:27:50:27 | pointer to free output argument | test_free.cpp:51:10:51:10 | a | Memory pointed to by $@ may already have been freed by $@. | test_free.cpp:51:10:51:10 | a | a | test_free.cpp:50:22:50:25 | call to free | call to free |
+| test_free.cpp:72:14:72:14 | a | test_free.cpp:69:10:69:10 | pointer to free output argument | test_free.cpp:72:14:72:14 | a | Memory pointed to by $@ may already have been freed by $@. | test_free.cpp:72:14:72:14 | a | a | test_free.cpp:69:5:69:8 | call to free | call to free |
+| test_free.cpp:85:12:85:12 | a | test_free.cpp:83:12:83:12 | pointer to operator delete output argument | test_free.cpp:85:12:85:12 | a | Memory pointed to by $@ may already have been freed by $@. | test_free.cpp:85:12:85:12 | a | a | test_free.cpp:83:5:83:13 | delete | delete |
+| test_free.cpp:103:10:103:10 | a | test_free.cpp:101:10:101:10 | pointer to free output argument | test_free.cpp:103:10:103:10 | a | Memory pointed to by $@ may already have been freed by $@. | test_free.cpp:103:10:103:10 | a | a | test_free.cpp:101:5:101:8 | call to free | call to free |
+| test_free.cpp:129:10:129:11 | * ... | test_free.cpp:128:10:128:11 | pointer to free output argument | test_free.cpp:129:10:129:11 | * ... | Memory pointed to by $@ may already have been freed by $@. | test_free.cpp:129:10:129:11 | * ... | * ... | test_free.cpp:128:5:128:8 | call to free | call to free |
+| test_free.cpp:154:10:154:10 | a | test_free.cpp:152:27:152:27 | pointer to free output argument | test_free.cpp:154:10:154:10 | a | Memory pointed to by $@ may already have been freed by $@. | test_free.cpp:154:10:154:10 | a | a | test_free.cpp:152:22:152:25 | call to free | call to free |
+| test_free.cpp:209:10:209:10 | a | test_free.cpp:207:10:207:10 | pointer to free output argument | test_free.cpp:209:10:209:10 | a | Memory pointed to by $@ may already have been freed by $@. | test_free.cpp:209:10:209:10 | a | a | test_free.cpp:207:5:207:8 | call to free | call to free |
+| test_free.cpp:302:12:302:14 | buf | test_free.cpp:301:12:301:14 | pointer to g_free output argument | test_free.cpp:302:12:302:14 | buf | Memory pointed to by $@ may already have been freed by $@. | test_free.cpp:302:12:302:14 | buf | buf | test_free.cpp:301:5:301:10 | call to g_free | call to g_free |