diff --git a/tests/15library.tests b/tests/15library.tests
index e289c71ec..3aa51767f 100644
--- a/tests/15library.tests
+++ b/tests/15library.tests
@@ -150,6 +150,7 @@ out: ID<Fork>-Fork.0..
 out: ID<Fork>-special
 out: sizeof\( idi::EntryID<Fork> \) .+ =
 out: sizeof\( idi::BareEntryID \)   .+ =
+out: sizeof\( \w+[^\)]* \)   .+ =
 return: 0
 END
 
diff --git a/tests/library/hash-generator-test.cpp b/tests/library/hash-generator-test.cpp
index 4bcbebed1..b6ee9f1b2 100644
--- a/tests/library/hash-generator-test.cpp
+++ b/tests/library/hash-generator-test.cpp
@@ -78,6 +78,7 @@ namespace test{
        * 
        * This problem is especially dangerous when storing objects keyed
        * by a string-id, which is generated from running numbers.
+       * @remark as of 2018 the boost::hash function does not show this weakness anymore
        */
       void
       demonstrate_boost_hash_weakness ()
@@ -106,7 +107,10 @@ namespace test{
                 }
               hashValues[hashVal] = candidate;
             }
-          CHECK (0 < collisions, "boost::hash for strings is expected to produce collisions");
+          if  (0 < collisions)
+            cout << "boost::hash for strings produced "<<collisions<<" collisions. This is a known problem."<<endl;
+          else
+            cout << "SURPRISE. No collisions with the boost::hash function." <<endl;
         }