1 files changed, 4 insertions, 1 deletions
diff --git a/BaseTools/Source/Python/GenFds/FfsFileStatement.py b/BaseTools/Source/Python/GenFds/FfsFileStatement.py
index 9250361d14..9fb62b0a91 100644
--- a/BaseTools/Source/Python/GenFds/FfsFileStatement.py
+++ b/BaseTools/Source/Python/GenFds/FfsFileStatement.py
@@ -48,7 +48,7 @@ class FileStatement (FileStatementClassObject):
     #   @param  FvParentAddr Parent Fv base address
     #   @retval string       Generated FFS file name
     #
-    def GenFfs(self, Dict = {}, FvChildAddr=[], FvParentAddr=None, IsMakefile=False, FvName=None):
+    def GenFfs(self, Dict = None, FvChildAddr=[], FvParentAddr=None, IsMakefile=False, FvName=None):
 
         if self.NameGuid and self.NameGuid.startswith('PCD('):
             PcdValue = GenFdsGlobalVariable.GetPcdValue(self.NameGuid)
@@ -70,6 +70,9 @@ class FileStatement (FileStatementClassObject):
         if not os.path.exists(OutputDir):
             os.makedirs(OutputDir)
 
+        if Dict is None:
+            Dict = {}
+
         Dict.update(self.DefineVarDict)
         SectionAlignments = None
         if self.FvName: