diff --git a/src/lib/symbol.hpp b/src/lib/symbol.hpp
index 8cb615345..f94ec2e5c 100644
--- a/src/lib/symbol.hpp
+++ b/src/lib/symbol.hpp
@@ -123,6 +123,9 @@ namespace lib {
        
        Symbol& operator= (Symbol const&) = default;
        Symbol& operator= (Symbol &&)     = default;
+       
+       explicit operator bool()  const { return not empty(); }
+       bool empty()              const { return *this == BOTTOM; }
     };
   
   
diff --git a/tests/15library.tests b/tests/15library.tests
index fc78c4517..5131419cc 100644
--- a/tests/15library.tests
+++ b/tests/15library.tests
@@ -540,8 +540,8 @@ END
 TEST "Symbol_test" Symbol_test  <<END
 out: one
 out: sizeof. Literal.+  =   (4|8)
-out-lit: string
-out-lit: string
+out-lit: onenight
+out-lit: minus one
 out-lit: one....one
 return: 0
 END
diff --git a/tests/library/symbol-test.cpp b/tests/library/symbol-test.cpp
index 2258d1c18..40f9d1242 100644
--- a/tests/library/symbol-test.cpp
+++ b/tests/library/symbol-test.cpp
@@ -80,8 +80,10 @@ namespace test{
           CHECK (li2 != li3);
           CHECK (li3 != li2);
           
-          cout << typeStr (li1 + string("ce"))         << endl;
-          cout << typeStr (string("minus " +li1))      << endl;
+          CHECK ("string" == typeStr (li1 + string{"night"}));
+          CHECK ("string" == typeStr (string{"minus " +li1}));
+          cout << li1 + string{"night"} << endl;
+          cout << string{"minus " +li1} << endl;
           cout << li2+string("..") << string("..")+li2 << endl;
           
           CHECK (hash_value(li1) == hash_value(li2));
@@ -117,9 +119,17 @@ namespace test{
           CHECK (sy1.c() == sy2.c());
           
           Symbol sy3;
+          CHECK (not sy3);
+          CHECK (sy3 == "⟂");
           CHECK (isnil(sy3));
           CHECK (sy1 != sy3);
           
+          CHECK (not Symbol{"⟂"});
+          CHECK (sy3 == Symbol{"⟂"});
+          CHECK (sy3.c() == Symbol{"⟂"}.c());
+          CHECK (Symbol{}.c() == Symbol{"⟂"}.c());
+          
+          // re-assignment
           sy3 = Symbol{l1};
           CHECK (!isnil(sy3));
           CHECK (sy1 == sy3);