diff --git a/backends/platform/symbian/symbian_builder/mmp_gen.py b/backends/platform/symbian/symbian_builder/mmp_gen.py
index f1fd1d6659c..5957d90bb79 100644
--- a/backends/platform/symbian/symbian_builder/mmp_gen.py
+++ b/backends/platform/symbian/symbian_builder/mmp_gen.py
@@ -247,6 +247,7 @@ def MakeMMP(engine):
    staticlib = tt[1]
 
    src = processModule_mk(pth, macrolist)
+   src = ProcessDup(src)
    src = FilterSrcs(src, engine)
 
    mmp = """TARGET scummvm_%s.lib
@@ -265,8 +266,6 @@ SOURCEPATH   ..\..\..\..\engines\%s\n
    if mmp is None:
       return
 
-   src = ProcessDup(src)
-
    plugins_table = """
 #if PLUGIN_ENABLED_STATIC(%s)
 LINK_PLUGIN(%s)