diff --git a/llvm/include/llvm/BinaryFormat/COFF.h b/llvm/include/llvm/BinaryFormat/COFF.h
--- a/llvm/include/llvm/BinaryFormat/COFF.h
+++ b/llvm/include/llvm/BinaryFormat/COFF.h
@@ -547,7 +547,7 @@
   uint32_t AddressOfEntryPoint; // RVA
   uint32_t BaseOfCode;          // RVA
   uint32_t BaseOfData;          // RVA
-  uint32_t ImageBase;
+  uint64_t ImageBase;
   uint32_t SectionAlignment;
   uint32_t FileAlignment;
   uint16_t MajorOperatingSystemVersion;
@@ -563,10 +563,10 @@
   uint16_t Subsystem;
   // FIXME: This should be DllCharacteristics to match the COFF spec.
   uint16_t DLLCharacteristics;
-  uint32_t SizeOfStackReserve;
-  uint32_t SizeOfStackCommit;
-  uint32_t SizeOfHeapReserve;
-  uint32_t SizeOfHeapCommit;
+  uint64_t SizeOfStackReserve;
+  uint64_t SizeOfStackCommit;
+  uint64_t SizeOfHeapReserve;
+  uint64_t SizeOfHeapCommit;
   uint32_t LoaderFlags;
   // FIXME: This should be NumberOfRvaAndSizes to match the COFF spec.
   uint32_t NumberOfRvaAndSize;
diff --git a/llvm/test/tools/yaml2obj/COFF/basic-arm64.yaml b/llvm/test/tools/yaml2obj/COFF/basic-arm64.yaml
--- a/llvm/test/tools/yaml2obj/COFF/basic-arm64.yaml
+++ b/llvm/test/tools/yaml2obj/COFF/basic-arm64.yaml
@@ -3,7 +3,9 @@
 # RUN: obj2yaml %t | FileCheck %s --check-prefix=ROUNDTRIP
 
 # CHECK: OptionalHeaderSize: 240
+# CHECK: ImageBase: 0x140000000
 
+# ROUNDTRIP: ImageBase: 5368709120
 # ROUNDTRIP: VirtualAddress:  4096
 # ROUNDTRIP: VirtualAddress:  8192
 # ROUNDTRIP: VirtualAddress:  12288
@@ -11,7 +13,7 @@
 --- !COFF
 OptionalHeader:
   AddressOfEntryPoint: 4096
-  ImageBase:       1073741824
+  ImageBase:       5368709120
   SectionAlignment: 4096
   FileAlignment:   512
   MajorOperatingSystemVersion: 6