Index: test/tools/llvm-objdump/file-headers-coff.test
===================================================================
--- test/tools/llvm-objdump/file-headers-coff.test
+++ test/tools/llvm-objdump/file-headers-coff.test
@@ -10,4 +10,4 @@
 symbols:
 
 # CHECK: architecture: i386
-# CHECK: start address: 0x0000
+# CHECK: start address: 0x00000000
Index: test/tools/llvm-objdump/file-headers-elf.test
===================================================================
--- test/tools/llvm-objdump/file-headers-elf.test
+++ test/tools/llvm-objdump/file-headers-elf.test
@@ -8,7 +8,7 @@
   Data:            ELFDATA2LSB
   Type:            ET_REL
   Machine:         EM_X86_64
-  Entry:           0x123456
+  Entry:           0x123456789abcde
 
 # CHECK: architecture: x86_64
-# CHECK: start address: 0x00123456
+# CHECK: start address: 0x00123456789abcde
Index: test/tools/llvm-objdump/file-headers-pe.test
===================================================================
--- test/tools/llvm-objdump/file-headers-pe.test
+++ test/tools/llvm-objdump/file-headers-pe.test
@@ -7,7 +7,7 @@
   Machine: IMAGE_FILE_MACHINE_I386
   Characteristics: [ IMAGE_FILE_DEBUG_STRIPPED ]
 OptionalHeader:
-  AddressOfEntryPoint: 0x1234
+  AddressOfEntryPoint: 0x123456
 # Unfortunately, all these flags are mandatory to set AddressOfEntryPoint.
 # All the values are randomly picked. They can't interfere in what
 # we are testing here.
@@ -30,4 +30,4 @@
 symbols:
 
 # CHECK: architecture: i386
-# CHECK: start address: 0x1234
+# CHECK: start address: 0x00123456
Index: tools/llvm-objdump/llvm-objdump.cpp
===================================================================
--- tools/llvm-objdump/llvm-objdump.cpp
+++ tools/llvm-objdump/llvm-objdump.cpp
@@ -2220,8 +2220,11 @@
   Expected<uint64_t> StartAddrOrErr = o->getStartAddress();
   if (!StartAddrOrErr)
     report_error(o->getFileName(), StartAddrOrErr.takeError());
+
+  StringRef Fmt = o->getBytesInAddress() > 4 ? "%016" PRIx64 : "%08" PRIx64;
+  uint64_t Address = StartAddrOrErr.get();
   outs() << "start address: "
-         << format("0x%0*x", o->getBytesInAddress(), StartAddrOrErr.get())
+         << "0x" << format(Fmt.data(), Address)
          << "\n";
 }