diff --git a/qa/pcbnew/test_zone_filler.cpp b/qa/pcbnew/test_zone_filler.cpp
index d4a6744742..b7df2a35d3 100644
--- a/qa/pcbnew/test_zone_filler.cpp
+++ b/qa/pcbnew/test_zone_filler.cpp
@@ -214,7 +214,7 @@ BOOST_FIXTURE_TEST_CASE( RegressionZoneFillTests, ZONE_FILL_TEST_FIXTURE )
         if( violations.empty() )
         {
             BOOST_CHECK_EQUAL( 1, 1 );  // quiet "did not check any assertions" warning
-            BOOST_TEST_MESSAGE( wxString::Format( "Zone fill regression: %s passed", relPath ) );
+            BOOST_TEST_MESSAGE( (const char*)(wxString::Format( "Zone fill regression: %s passed", relPath ).utf8_str()) );
         }
         else
         {
@@ -227,7 +227,7 @@ BOOST_FIXTURE_TEST_CASE( RegressionZoneFillTests, ZONE_FILL_TEST_FIXTURE )
                                                      itemMap ) );
             }
 
-            BOOST_ERROR( wxString::Format( "Zone fill regression: %s failed", relPath ) );
+            BOOST_ERROR( (const char*)(wxString::Format( "Zone fill regression: %s failed", relPath ).utf8_str()) );
         }
     }
 }