diff --git a/src/common/db.cpp b/src/common/db.cpp
index a881c22c4c..be855ba25c 100644
--- a/src/common/db.cpp
+++ b/src/common/db.cpp
@@ -62,6 +62,8 @@ wxChar const *SQL_LOG_FILENAME         = wxT("sqllog.txt");
 wxChar const *SQL_CATALOG_FILENAME     = wxT("catalog.txt");
 
 #ifdef __WXDEBUG__
+    #include "wx/thread.h"
+
     extern wxList TablesInUse;
     extern wxCriticalSection csTablesInUse;
 #endif
diff --git a/src/common/dbtable.cpp b/src/common/dbtable.cpp
index 4cc6885802..423c1b5a98 100644
--- a/src/common/dbtable.cpp
+++ b/src/common/dbtable.cpp
@@ -59,6 +59,8 @@ ULONG lastTableID = 0;
 
 
 #ifdef __WXDEBUG__
+    #include "wx/thread.h"
+
     wxList TablesInUse;
     wxCriticalSection csTablesInUse;
 #endif