Index: llvm/lib/ObjectYAML/ELFEmitter.cpp
===================================================================
--- llvm/lib/ObjectYAML/ELFEmitter.cpp
+++ llvm/lib/ObjectYAML/ELFEmitter.cpp
@@ -225,7 +225,7 @@
   Header.e_machine = Doc.Header.Machine;
   Header.e_version = EV_CURRENT;
   Header.e_entry = Doc.Header.Entry;
-  Header.e_phoff = sizeof(Header);
+  Header.e_phoff = Doc.ProgramHeaders.size() ? sizeof(Header) : 0;
   Header.e_flags = Doc.Header.Flags;
   Header.e_ehsize = sizeof(Elf_Ehdr);
   Header.e_phentsize = sizeof(Elf_Phdr);
Index: llvm/test/tools/yaml2obj/elf-header-ephoff.yaml
===================================================================
--- /dev/null
+++ llvm/test/tools/yaml2obj/elf-header-ephoff.yaml
@@ -0,0 +1,13 @@
+## Check that e_phoff is set to 0 when there are no program headers
+
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-readobj --file-headers %t | FileCheck %s
+
+# CHECK: ProgramHeaderOffset: 0
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_X86_64