diff --git a/llvm/test/tools/yaml2obj/help.test b/llvm/test/tools/yaml2obj/help.test
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/yaml2obj/help.test
@@ -0,0 +1,11 @@
+## Show that help text is printed correctly when requested.
+
+# RUN: yaml2obj -h | FileCheck %s --check-prefixes=CHECK,CATEG --implicit-check-not=Options:
+# RUN: yaml2obj --help | FileCheck %s --check-prefixes=CHECK,CATEG --implicit-check-not=Options:
+# RUN: yaml2obj --help-list | FileCheck %s --implicit-check-not=Options:
+
+# CHECK: OVERVIEW: Create an object file from YAML description
+# CHECK: USAGE: yaml2obj{{(.exe)?}} [options] <input file>{{$}}
+# CHECK: OPTIONS:
+# CATEG: Generic Options:
+# CATEG: yaml2obj Options:
diff --git a/llvm/test/tools/yaml2obj/invalid-output-file.yaml b/llvm/test/tools/yaml2obj/invalid-output-file.yaml
deleted file mode 100644
--- a/llvm/test/tools/yaml2obj/invalid-output-file.yaml
+++ /dev/null
@@ -1,4 +0,0 @@
-# RUN: not yaml2obj -o %p/path/does/not/exist 2>&1 | FileCheck %s
-
-## Don't check the OS-dependent message "No such file or directory".
-# CHECK: yaml2obj: error: failed to open '{{.*}}/path/does/not/exist': {{.*}}
diff --git a/llvm/test/tools/yaml2obj/output-file.yaml b/llvm/test/tools/yaml2obj/output-file.yaml
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/yaml2obj/output-file.yaml
@@ -0,0 +1,19 @@
+## Test that -o sets the output file name.
+
+# RUN: rm -f %t
+# RUN: yaml2obj %s -o %t
+# RUN: ls %t
+# RUN: rm -f %t
+# RUN: yaml2obj %s -o%t
+# RUN: ls %t
+
+# RUN: not yaml2obj -o %p/path/does/not/exist 2>&1 | FileCheck %s
+
+# CHECK: yaml2obj: error: failed to open '{{.*}}/path/does/not/exist': {{[Nn]}}o such file or directory
+
+!ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_NONE
diff --git a/llvm/tools/yaml2obj/yaml2obj.cpp b/llvm/tools/yaml2obj/yaml2obj.cpp
--- a/llvm/tools/yaml2obj/yaml2obj.cpp
+++ b/llvm/tools/yaml2obj/yaml2obj.cpp
@@ -28,22 +28,28 @@
 
 using namespace llvm;
 
-static cl::opt<std::string>
-  Input(cl::Positional, cl::desc("<input>"), cl::init("-"));
+namespace {
+cl::OptionCategory Cat("yaml2obj Options");
 
-static cl::opt<unsigned>
+cl::opt<std::string> Input(cl::Positional, cl::desc("<input file>"),
+                           cl::init("-"), cl::cat(Cat));
+
+cl::opt<unsigned>
     DocNum("docnum", cl::init(1),
-           cl::desc("Read specified document from input (default = 1)"));
+           cl::desc("Read specified document from input (default = 1)"),
+           cl::cat(Cat));
 
-static cl::opt<std::string> OutputFilename("o", cl::desc("Output filename"),
-                                           cl::value_desc("filename"));
+cl::opt<std::string> OutputFilename("o", cl::desc("Output filename"),
+                                    cl::value_desc("filename"), cl::init("-"),
+                                    cl::Prefix, cl::cat(Cat));
+} // namespace
 
 int main(int argc, char **argv) {
   InitLLVM X(argc, argv);
-  cl::ParseCommandLineOptions(argc, argv);
-
-  if (OutputFilename.empty())
-    OutputFilename = "-";
+  cl::HideUnrelatedOptions(Cat);
+  cl::ParseCommandLineOptions(
+      argc, argv, "Create an object file from a YAML description", nullptr,
+      nullptr, /*LongOptionsUseDoubleDash=*/true);
 
   auto ErrHandler = [](const Twine &Msg) {
     WithColor::error(errs(), "yaml2obj") << Msg << "\n";