diff --git a/BaseTools/Source/Python/AutoGen/GenC.py b/BaseTools/Source/Python/AutoGen/GenC.py
index 9bdb0363b2..e73ba79e28 100644
--- a/BaseTools/Source/Python/AutoGen/GenC.py
+++ b/BaseTools/Source/Python/AutoGen/GenC.py
@@ -1319,11 +1319,13 @@ def CreateGuidDefinitionCode(Info, AutoGenC, AutoGenH):
 
     if Info.GuidList:
         AutoGenC.Append("\n// Guids\n")
+        AutoGenH.Append("\n// Guids\n")
     #
     # GUIDs
     #
     for Key in Info.GuidList:
         AutoGenC.Append('GLOBAL_REMOVE_IF_UNREFERENCED %s %s = %s;\n' % (GuidType, Key, Info.GuidList[Key]))
+        AutoGenH.Append('extern %s %s;\n' % (GuidType, Key))
 
 ## Create code for protocol
 #
@@ -1342,11 +1344,13 @@ def CreateProtocolDefinitionCode(Info, AutoGenC, AutoGenH):
 
     if Info.ProtocolList:
         AutoGenC.Append("\n// Protocols\n")
+        AutoGenH.Append("\n// Protocols\n")
     #
     # Protocol GUIDs
     #
     for Key in Info.ProtocolList:
         AutoGenC.Append('GLOBAL_REMOVE_IF_UNREFERENCED %s %s = %s;\n' % (GuidType, Key, Info.ProtocolList[Key]))
+        AutoGenH.Append('extern %s %s;\n' % (GuidType, Key))
 
 ## Create code for PPI
 #
@@ -1365,11 +1369,13 @@ def CreatePpiDefinitionCode(Info, AutoGenC, AutoGenH):
 
     if Info.PpiList:
         AutoGenC.Append("\n// PPIs\n")
+        AutoGenH.Append("\n// PPIs\n")
     #
     # PPI GUIDs
     #
     for Key in Info.PpiList:
         AutoGenC.Append('GLOBAL_REMOVE_IF_UNREFERENCED %s %s = %s;\n' % (GuidType, Key, Info.PpiList[Key]))
+        AutoGenH.Append('extern %s %s;\n' % (GuidType, Key))
 
 ## Create code for PCD
 #