diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 66ed440..7502340 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -62,9 +62,10 @@ compile inherit.cpp ;
 compile insert.cpp ;
 compile insert_range.cpp ;
 run int.cpp ;
-run char.cpp ;
-run integral_c.cpp
-  : : : <toolset>vacpp:<cxxflags>-qchars=signed ;
+run char.cpp : : :                                                                    : char                ;
+run char.cpp : : : <toolset>gcc:<cxxflags>"-funsigned-char -Wnarrowing -Werror"       : char_unsigned       ;
+run integral_c.cpp : : : <toolset>vacpp:<cxxflags>-qchars=signed                      : integral_c          ;
+run integral_c.cpp : : : <toolset>gcc:<cxxflags>"-funsigned-char -Wnarrowing -Werror" : integral_c_unsigned ;
 compile is_placeholder.cpp ;
 compile is_sequence.cpp ;
 compile iterator_tags.cpp ;