Index: include/llvm/Support/YAMLTraits.h
===================================================================
--- include/llvm/Support/YAMLTraits.h
+++ include/llvm/Support/YAMLTraits.h
@@ -587,10 +587,12 @@
 
   // allow anonymous enum values to be used with LLVM_YAML_STRONG_TYPEDEF
   template <typename T>
-  void enumCase(T &Val, const char* Str, const uint32_t ConstVal) {
+  bool enumCase(T &Val, const char* Str, const uint32_t ConstVal) {
     if ( matchEnumScalar(Str, outputting() && Val == static_cast<T>(ConstVal)) ) {
       Val = ConstVal;
+      return true;
     }
+    return false;
   }
 
   template <typename FBT, typename T>
Index: lib/ObjectYAML/ELFYAML.cpp
===================================================================
--- lib/ObjectYAML/ELFYAML.cpp
+++ lib/ObjectYAML/ELFYAML.cpp
@@ -11,6 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/ADT/StringExtras.h"
 #include "llvm/ObjectYAML/ELFYAML.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/MipsABIFlags.h"
@@ -505,7 +506,7 @@
     IO &IO, ELFYAML::ELF_REL &Value) {
   const auto *Object = static_cast<ELFYAML::Object *>(IO.getContext());
   assert(Object && "The IO context is not initialized");
-#define ELF_RELOC(X, Y) IO.enumCase(Value, #X, ELF::X);
+#define ELF_RELOC(X, Y) if (IO.enumCase(Value, #X, ELF::X)) return;
   switch (Object->Header.Machine) {
   case ELF::EM_X86_64:
 #include "llvm/BinaryFormat/ELFRelocs/x86_64.def"
@@ -542,6 +543,19 @@
     llvm_unreachable("Unsupported architecture");
   }
 #undef ELF_RELOC
+
+  // If we failed to match relocation by enum name,
+  // use integer representation instead.
+  if (!IO.outputting()) {
+    StringRef S;
+    IO.blockScalarString(S);
+    uint32_t Type;
+    if (to_integer(S, Type))
+      IO.enumCase(Value, S.str().data(), Type);
+  } else {
+    std::string Val = std::to_string(Value);
+    IO.enumCase(Value, Val.data(), Value);
+  }
 }
 
 void ScalarEnumerationTraits<ELFYAML::MIPS_AFL_REG>::enumeration(
Index: test/Object/X86/yaml-elf-x86-rel-broken.yaml
===================================================================
--- test/Object/X86/yaml-elf-x86-rel-broken.yaml
+++ test/Object/X86/yaml-elf-x86-rel-broken.yaml
@@ -0,0 +1,48 @@
+# RUN: yaml2obj %s > %t
+# RUN: obj2yaml %t | FileCheck %s
+
+# CHECK:      --- !ELF
+# CHECK-NEXT: FileHeader:
+# CHECK-NEXT:   Class:           ELFCLASS32
+# CHECK-NEXT:   Data:            ELFDATA2LSB
+# CHECK-NEXT:   Type:            ET_REL
+# CHECK-NEXT:   Machine:         EM_386
+# CHECK-NEXT: Sections:
+# CHECK-NEXT:   - Name:            .text
+# CHECK-NEXT:     Type:            SHT_PROGBITS
+# CHECK-NEXT:     Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+# CHECK-NEXT:     AddressAlign:    0x0000000000000004
+# CHECK-NEXT:     Content:         '0000000000000000'
+# CHECK-NEXT:   - Name:            .rel.text
+# CHECK-NEXT:     Type:            SHT_REL
+# CHECK-NEXT:     Link:            .symtab
+# CHECK-NEXT:     AddressAlign:    0x0000000000000004
+# CHECK-NEXT:     Info:            .text
+# CHECK-NEXT:     Relocations:
+# CHECK-NEXT:       - Offset:          0x0000000000000000
+# CHECK-NEXT:         Symbol:          ''
+# CHECK-NEXT:         Type:            255
+# CHECK-NEXT: Symbols:
+# CHECK-NEXT: ...
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS32
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_386
+Sections:
+  - Type:            SHT_PROGBITS
+    Name:            .text
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x04
+    Content:         0000000000000000
+  - Type:            SHT_REL
+    Name:            .rel.text
+    Link:            .symtab
+    Info:            .text
+    AddressAlign:    0x04
+    Relocations:
+      - Offset:          0
+        Symbol:          main
+        Type:            0xFF