diff --git a/eeschema/sch_legacy_plugin.cpp b/eeschema/sch_legacy_plugin.cpp
index 25fb3c18ec..fd4c1d5255 100644
--- a/eeschema/sch_legacy_plugin.cpp
+++ b/eeschema/sch_legacy_plugin.cpp
@@ -2168,7 +2168,7 @@ void SCH_LEGACY_PLUGIN_CACHE::loadHeader( FILE_LINE_READER& aReader )
 {
     const char* line = aReader.Line();
 
-    wxCHECK( strCompare( "$HEADER", line, &line ), NULL );
+    wxASSERT( strCompare( "$HEADER", line, &line ) );
 
     while( aReader.ReadLine() )
     {