diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 945fba8dca8..574474c118e 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -153,10 +153,10 @@ DIType DbgVariable::getType() const {
 } // end llvm namespace
 
 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
-  : Asm(A), MMI(Asm->MMI), FirstCU(0), FissionCU(0),
+  : Asm(A), MMI(Asm->MMI), FirstCU(0),
     AbbreviationsSet(InitAbbreviationsSetSize),
     SourceIdMap(DIEValueAllocator), StringPool(DIEValueAllocator),
-    PrevLabel(NULL), GlobalCUIndexCount(0) {
+    PrevLabel(NULL), GlobalCUIndexCount(0), FissionCU(0) {
   NextStringPoolNumber = 0;
 
   DwarfInfoSectionSym = DwarfAbbrevSectionSym = 0;
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 689ccca655b..56b9218474a 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -205,9 +205,6 @@ class DwarfDebug {
 
   CompileUnit *FirstCU;
 
-  // The CU left in the original object file for Fission debug info.
-  CompileUnit *FissionCU;
-
   // Maps MDNode with its corresponding CompileUnit.
   DenseMap <const MDNode *, CompileUnit *> CUMap;
 
@@ -322,6 +319,15 @@ class DwarfDebug {
   // DWARF5 Experimental Options
   bool HasDwarfAccelTables;
   bool HasDwarfFission;
+
+  // Fission Variables
+  // In general these will all be for bits that are left in the
+  // original object file, rather than things that are meant
+  // to be in the .dwo sections.
+
+  // The CU left in the original object file for Fission debug info.
+  CompileUnit *FissionCU;
+
 private:
 
   /// \brief Define a unique number for the abbreviation.