diff --git a/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 97f251086ae..82e9bb008a0 100644
--- a/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1766,12 +1766,12 @@ void DwarfUnit::constructArrayTypeDIE(DIE &Buffer, DICompositeType CTy) {
   // as different languages may have different sizes for indexes.
   DIE *IdxTy = getIndexTyDie();
   if (!IdxTy) {
-    // Construct an anonymous type for index type.
+    // Construct an integer type to use for indexes.
     IdxTy = createAndAddDIE(dwarf::DW_TAG_base_type, *UnitDie);
-    addString(IdxTy, dwarf::DW_AT_name, "int");
-    addUInt(IdxTy, dwarf::DW_AT_byte_size, None, sizeof(int32_t));
+    addString(IdxTy, dwarf::DW_AT_name, "sizetype");
+    addUInt(IdxTy, dwarf::DW_AT_byte_size, None, sizeof(int64_t));
     addUInt(IdxTy, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1,
-            dwarf::DW_ATE_signed);
+            dwarf::DW_ATE_unsigned);
     setIndexTyDie(IdxTy);
   }
 
diff --git a/test/DebugInfo/X86/empty-array.ll b/test/DebugInfo/X86/empty-array.ll
index 461b9da3add..3fab313fe0e 100644
--- a/test/DebugInfo/X86/empty-array.ll
+++ b/test/DebugInfo/X86/empty-array.ll
@@ -21,8 +21,8 @@
 ; CHECK: [[BASETYPE]]: DW_TAG_base_type
 ; CHECK: [[BASE2]]: DW_TAG_base_type
 ; CHECK-NEXT: DW_AT_name
-; CHECK-NEXT: DW_AT_byte_size [DW_FORM_data1]  (0x04)
-; CHECK-NEXT: DW_AT_encoding [DW_FORM_data1]   (0x05)
+; CHECK-NEXT: DW_AT_byte_size [DW_FORM_data1]  (0x08)
+; CHECK-NEXT: DW_AT_encoding [DW_FORM_data1]   (0x07)
 
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!21}
diff --git a/test/DebugInfo/X86/nondefault-subrange-array.ll b/test/DebugInfo/X86/nondefault-subrange-array.ll
index b097578a6e2..4df1bd4847d 100644
--- a/test/DebugInfo/X86/nondefault-subrange-array.ll
+++ b/test/DebugInfo/X86/nondefault-subrange-array.ll
@@ -23,9 +23,9 @@
 
 ; CHECK: [[BASE]]: DW_TAG_base_type
 ; CHECK: [[BASE2]]: DW_TAG_base_type
-; CHECK-NEXT:                 DW_AT_name [DW_FORM_strp]       ( .debug_str[0x{{[0-9a-f]*}}] = "int")
-; CHECK-NEXT:                 DW_AT_byte_size [DW_FORM_data1] (0x04)
-; CHECK-NEXT:                 DW_AT_encoding [DW_FORM_data1]  (0x05)
+; CHECK-NEXT:                 DW_AT_name [DW_FORM_strp]       ( .debug_str[0x{{[0-9a-f]*}}] = "sizetype")
+; CHECK-NEXT:                 DW_AT_byte_size [DW_FORM_data1] (0x08)
+; CHECK-NEXT:                 DW_AT_encoding [DW_FORM_data1]  (0x07)
 
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!21}