diff --git a/qt6-after/qt6-migrated-legatus/Lts/Services/FilterManagement/CMakeLists.txt b/qt6-after/qt6-migrated-legatus/Lts/Services/FilterManagement/CMakeLists.txt
index f8a36c642..822d34801 100755
--- a/qt6-after/qt6-migrated-legatus/Lts/Services/FilterManagement/CMakeLists.txt
+++ b/qt6-after/qt6-migrated-legatus/Lts/Services/FilterManagement/CMakeLists.txt
@@ -7,6 +7,12 @@
 INCLUDE(MacroRTIDDSGen)
 INCLUDE(MacroCodeGenIdl)
 
+# Resolve <DDS/...> includes (generic_data_reader.h, generic_dtc.h, ...) to the
+# real headers under Lts/DDS/ instead of the migration stub tree in include/.
+# Qt5 legacy resolved these the same way; the stub tree shadows them otherwise
+# (it opens namespace DDSGeneric around framework includes and breaks Qt6).
+include_directories(BEFORE ${CMAKE_SOURCE_DIR}/Lts)
+
 SET(xml_FILE flt_service.xml)
 
 #
@@ -19,26 +25,18 @@ SET(SRCS_common
 )
 
 # Generate flt_enums.idl / flt.idl
-IF(BUILD_RTI)
-  CODEGEN_IDL_SVC(SRCS_common ${xml_FILE})
-ENDIF()
+CODEGEN_IDL_SVC(SRCS_common ${xml_FILE})
 # Generate flt_db_impl.cpp/.h, flt_db.h
-IF(BUILD_RTI)
-  CODEGEN_DATABASE(SRCS_common ${xml_FILE})
-ENDIF()
+CODEGEN_DATABASE(SRCS_common ${xml_FILE})
 
 # Generate *.cpp/*.hpp from idl
 RTIDDSGEN(SRCS_common flt_enums.idl)
 RTIDDSGEN(SRCS_common flt.idl)
 
 # Generate flt_dt[s,c]_types.h, flt_ft[s,c]_types.h
-IF(BUILD_RTI)
-  CODEGEN_TOPIC_TYPEDEFS(SRCS_common ${xml_FILE})
-ENDIF()
+CODEGEN_TOPIC_TYPEDEFS(SRCS_common ${xml_FILE})
 # Generate flt_[d|f]tc.h
-IF(BUILD_RTI)
-  CODEGEN_CLIENT_TOPICS_IFC(SRCS_common ${xml_FILE})
-ENDIF()
+CODEGEN_CLIENT_TOPICS_IFC(SRCS_common ${xml_FILE})
 
 NGL_ADD_LIBRARY(AAR SV WS svcFltCommon SHARED  ${SRCS_common})
 NGL_TARGET_INCLUDE_DIRECTORIES(svcFltCommon
@@ -64,9 +62,7 @@ SET(SRCS_client
   flt_export.h
 )
 # generate flt_[d|f]tc.h, flt_[d|f]tc_impl.[cpp|h]
-IF(BUILD_RTI)
-  CODEGEN_CLIENT_TOPICS_IMPL(SRCS_client ${xml_FILE})
-ENDIF()
+CODEGEN_CLIENT_TOPICS_IMPL(SRCS_client ${xml_FILE})
 
 NGL_ADD_LIBRARY(AAR SV WS svcFltClient SHARED ${SRCS_client})
 NGL_TARGET_INCLUDE_DIRECTORIES(svcFltClient
@@ -107,13 +103,9 @@ SET(SRCS_server
   ${xml_FILE}
 )
 # generate flt_[d|f]ts.h, flt_[d|f]ts_impl.[cpp|h]
-IF(BUILD_RTI)
-  CODEGEN_SERVER_TOPICS(SRCS_server ${xml_FILE})
-ENDIF()
+CODEGEN_SERVER_TOPICS(SRCS_server ${xml_FILE})
 # Generate flt.sql, flt.xml
-IF(BUILD_RTI)
-  CODEGEN_SQL(SRCS_server ${xml_FILE})
-ENDIF()
+CODEGEN_SQL(SRCS_server ${xml_FILE})
 
 NGL_ADD_LIBRARY(AAR SV svcFltServer SHARED ${SRCS_server})
 NGL_TARGET_INCLUDE_DIRECTORIES(svcFltServer
@@ -141,9 +133,7 @@ NGL_INSTALL_TARGET(svcFltServer)
 #
 # --- Topic Type Plugin --------------------------------------------------------------
 #
-IF(BUILD_RTI)
-  CREATE_TOPIC_TYPE_PLUGIN(${xml_FILE})
-ENDIF()
+CREATE_TOPIC_TYPE_PLUGIN(${xml_FILE})
 
 #
 # --- Executable -------------------------------------------------