diff --git a/common/project/net_settings.cpp b/common/project/net_settings.cpp
index d67c510c82..ac5cdaebb7 100644
--- a/common/project/net_settings.cpp
+++ b/common/project/net_settings.cpp
@@ -408,6 +408,7 @@ std::shared_ptr<NETCLASS> NET_SETTINGS::GetEffectiveNetClass( const wxString& aN
         }
     }
 
+    m_NetClassPatternAssignmentCache[ aNetName ] = wxEmptyString;
     return m_DefaultNetClass;
 }