diff --git a/reactos/cmake/midl-support.cmake b/reactos/cmake/midl-support.cmake
index 8ae461a28d1..93fab81df48 100644
--- a/reactos/cmake/midl-support.cmake
+++ b/reactos/cmake/midl-support.cmake
@@ -9,98 +9,102 @@ else()
 endif()
 
 function(add_typelib)
-    get_includes(INCLUDES)
-    get_defines(DEFINES)
-    foreach(FILE ${ARGN})
-        get_filename_component(NAME ${FILE} NAME_WE)
+    get_includes(_includes)
+    get_defines(_defines)
+    foreach(_idl_file ${ARGN})
+        get_filename_component(_name_we ${_idl_file} NAME_WE)
         add_custom_command(
-            OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${NAME}.tlb
-            COMMAND midl ${INCLUDES} ${DEFINES} ${IDL_FLAGS} /tlb ${CMAKE_CURRENT_BINARY_DIR}/${NAME}.tlb ${CMAKE_CURRENT_SOURCE_DIR}/${FILE}
-            DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/${FILE})
+            OUTPUT ${_name_we}.tlb
+            COMMAND midl ${_includes} ${_defines} ${IDL_FLAGS} /tlb ${_name_we}.tlb ${CMAKE_CURRENT_SOURCE_DIR}/${_idl_file}
+            DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/${_idl_file})
     endforeach()
 endfunction()
 
 function(add_idl_headers TARGET)
-    get_includes(INCLUDES)
-    get_defines(DEFINES)
-    foreach(_input_file ${ARGN})
-        get_filename_component(_name ${_input_file} NAME_WE)
-        set(_name ${CMAKE_CURRENT_BINARY_DIR}/${_name})
+    get_includes(_includes)
+    get_defines(_defines)
+    foreach(_idl_file ${ARGN})
+        get_filename_component(_name_we ${_idl_file} NAME_WE)
+        #set(_name ${CMAKE_CURRENT_BINARY_DIR}/${_name_we})
         add_custom_command(
-            OUTPUT ${_name}.h
-            COMMAND midl ${INCLUDES} ${DEFINES} ${IDL_FLAGS} /h ${_name}.h /iid ${_name}_dummy_i.h ${CMAKE_CURRENT_SOURCE_DIR}/${_input_file}
-            DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/${_input_file})
-        list(APPEND _target_dependencies ${_name}.h)
+            OUTPUT ${_name_we}.h ${_name_we}_dummy_i.c
+            COMMAND midl ${_includes} ${_defines} ${IDL_FLAGS} /h ${_name_we}.h /iid ${_name_we}_dummy_i.c ${CMAKE_CURRENT_SOURCE_DIR}/${_idl_file}
+            DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/${_idl_file})
+        list(APPEND _target_dependencies ${_name_we}.h)
     endforeach()
     add_custom_target(${TARGET} DEPENDS ${_target_dependencies})
 endfunction()
 
 function(add_rpcproxy_files)
-    get_includes(INCLUDES)
-    get_defines(DEFINES)
-    set(OUTPUT_FILES "")
-    foreach(FILE ${ARGN})
-        get_filename_component(NAME ${FILE} NAME_WE)
+    get_includes(_includes)
+    get_defines(_defines)
+    set(_output_files "")
+    foreach(_idl_file ${ARGN})
+        get_filename_component(_name_we ${_idl_file} NAME_WE)
         add_custom_command(
-            OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${NAME}_p.c ${CMAKE_CURRENT_BINARY_DIR}/${NAME}_p.h ${CMAKE_CURRENT_BINARY_DIR}/proxy.dlldata.c
-            COMMAND midl ${INCLUDES} ${DEFINES} ${IDL_FLAGS} /proxy ${CMAKE_CURRENT_BINARY_DIR}/${NAME}_p.c /h ${NAME}_p.h ${CMAKE_CURRENT_SOURCE_DIR}/${FILE} /dlldata ${CMAKE_CURRENT_BINARY_DIR}/proxy.dlldata.c
-            DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/${FILE} ${OUTPUT_FILES})
-        list(APPEND OUTPUT_FILES ${CMAKE_CURRENT_BINARY_DIR}/${NAME}_p.c)
-        list(APPEND OUTPUT_FILES ${CMAKE_CURRENT_BINARY_DIR}/${NAME}_p.h)
+            OUTPUT ${_name_we}_p.c ${_name_we}_p.h proxy.dlldata.c
+            COMMAND midl ${_includes} ${_defines} ${IDL_FLAGS} /proxy ${_name_we}_p.c /h ${_name_we}_p.h /dlldata proxy.dlldata.c ${CMAKE_CURRENT_SOURCE_DIR}/${_idl_file}
+            DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/${_idl_file} ${_output_files})
+        list(APPEND _output_files ${CMAKE_CURRENT_BINARY_DIR}/${_name_we}_p.c)
+        list(APPEND _output_files ${CMAKE_CURRENT_BINARY_DIR}/${_name_we}_p.h)
     endforeach()
     set_source_files_properties(${CMAKE_CURRENT_BINARY_DIR}/proxy.dlldata.c PROPERTIES GENERATED TRUE)
 endfunction()
 
-function(add_rpc_files __type)
-    get_includes(INCLUDES)
-    get_defines(DEFINES)
+function(add_rpc_files _type)
+    get_includes(_includes)
+    get_defines(_defines)
     # Is it a client or server module?
-    if(__type STREQUAL server)
-        set(__server_client /sstub)
-        set(__suffix _s)
-    elseif(__type STREQUAL client)
-        set(__server_client /cstub)
-        set(__suffix _c)
+    if(_type STREQUAL server)
+        set(_server_client /sstub)
+        set(_suffix _s)
+    elseif(_type STREQUAL client)
+        set(_server_client /cstub)
+        set(_suffix _c)
     else()
         message(FATAL_ERROR "Please pass either server or client as argument to add_rpc_files")
     endif()
     foreach(FILE ${ARGN})
-        get_filename_component(__name ${FILE} NAME_WE)
-        set(__name ${CMAKE_CURRENT_BINARY_DIR}/${__name}${__suffix})
+        get_filename_component(_name_we ${FILE} NAME_WE)
+        set(_name_we ${CMAKE_CURRENT_BINARY_DIR}/${_name_we}${_suffix})
         if(NOT IS_ABSOLUTE ${FILE})
             set(FILE ${CMAKE_CURRENT_SOURCE_DIR}/${FILE})
         endif()
         add_custom_command(
-            OUTPUT ${__name}.c ${__name}.h
-            COMMAND midl ${INCLUDES} ${DEFINES} ${IDL_FLAGS} /h ${__name}.h ${__server_client} ${__name}.c ${FILE}
+            OUTPUT ${_name_we}.c ${_name_we}.h
+            COMMAND midl ${_includes} ${_defines} ${IDL_FLAGS} /h ${_name_we}.h ${_server_client} ${_name_we}.c ${FILE}
             DEPENDS ${FILE})
     endforeach()
 endfunction()
 
-function(generate_idl_iids IDL_FILE)
-    get_filename_component(FILE ${IDL_FILE} NAME)
-    if(FILE STREQUAL "${IDL_FILE}")
-        set(IDL_FILE_FULL "${CMAKE_CURRENT_SOURCE_DIR}/${IDL_FILE}")
-    else()
-        set(IDL_FILE_FULL ${IDL_FILE})
-    endif()
-    get_includes(INCLUDES)
-    get_defines(DEFINES)
-    get_filename_component(NAME ${IDL_FILE} NAME_WE)
+function(generate_idl_iids _idl_file)
+    get_includes(_includes)
+    get_defines(_defines)
+
+    get_filename_component(_name ${_idl_file} NAME)
+    #if(_name STREQUAL "${_idl_file}")
+    #    set(_idl_file "${CMAKE_CURRENT_SOURCE_DIR}/${_idl_file}")
+    #endif()
+
+    get_filename_component(_name_we ${_idl_file} NAME_WE)
     add_custom_command(
-        OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${NAME}_i.c
-        COMMAND midl ${INCLUDES} ${DEFINES} ${IDL_FLAGS} /iid ${CMAKE_CURRENT_BINARY_DIR}/${NAME}_i.c ${IDL_FILE_FULL}
-        DEPENDS ${IDL_FILE_FULL})
-    set_source_files_properties(${CMAKE_CURRENT_BINARY_DIR}/${NAME}_i.c PROPERTIES GENERATED TRUE)
+        OUTPUT ${_name_we}_i.c ${_name_we}_i.h
+        COMMAND midl ${_includes} ${_defines} ${IDL_FLAGS} /h ${_name_we}_i.h /iid ${_name_we}_i.c ${_idl_file}
+        DEPENDS ${_idl_file})
+    set_source_files_properties(${CMAKE_CURRENT_BINARY_DIR}/${_name_we}_i.c PROPERTIES GENERATED TRUE)
 endfunction()
 
-function(add_iid_library TARGET)
-    foreach(IDL_FILE ${ARGN})
-        get_filename_component(NAME ${IDL_FILE} NAME_WE)
-        generate_idl_iids(${IDL_FILE})
-        list(APPEND IID_SOURCES ${NAME}_i.c)
+function(add_iid_library _target)
+
+    foreach(_idl_file ${ARGN})
+        generate_idl_iids(${_idl_file})
+        get_filename_component(_name_we ${_idl_file} NAME_WE)
+        list(APPEND _iid_sources ${CMAKE_CURRENT_BINARY_DIR}/${_name_we}_i.c)
     endforeach()
-    add_library(${TARGET} ${IID_SOURCES})
-	add_dependencies(${TARGET} psdk)
-    set_target_properties(${TARGET} PROPERTIES EXCLUDE_FROM_ALL TRUE)
+    add_library(${_target} ${_iid_sources})
+
+    # for wtypes.h
+	add_dependencies(${_target} psdk)
+
+    set_target_properties(${_target} PROPERTIES EXCLUDE_FROM_ALL TRUE)
 endfunction()