diff --git a/lld/MachO/ConcatOutputSection.h b/lld/MachO/ConcatOutputSection.h
--- a/lld/MachO/ConcatOutputSection.h
+++ b/lld/MachO/ConcatOutputSection.h
@@ -51,7 +51,7 @@
   }
 
 private:
-  void mergeFlags(InputSection *input);
+  void finalizeFlags(InputSection *input);
 
   size_t size = 0;
   uint64_t fileSize = 0;
diff --git a/lld/MachO/ConcatOutputSection.cpp b/lld/MachO/ConcatOutputSection.cpp
--- a/lld/MachO/ConcatOutputSection.cpp
+++ b/lld/MachO/ConcatOutputSection.cpp
@@ -31,7 +31,7 @@
     flags = input->flags;
   } else {
     align = std::max(align, input->align);
-    mergeFlags(input);
+    finalizeFlags(input);
   }
   inputs.push_back(input);
   input->parent = this;
@@ -335,28 +335,54 @@
   }
 }
 
-// TODO: this is most likely wrong; reconsider how section flags
-// are actually merged. The logic presented here was written without
-// any form of informed research.
-void ConcatOutputSection::mergeFlags(InputSection *input) {
-  uint8_t baseType = flags & SECTION_TYPE;
-  uint8_t inputType = input->flags & SECTION_TYPE;
-  if (baseType != inputType)
-    error("Cannot merge section " + input->name + " (type=0x" +
-          to_hexString(inputType) + ") into " + name + " (type=0x" +
-          to_hexString(baseType) + "): inconsistent types");
-
-  constexpr uint32_t strictFlags = S_ATTR_DEBUG | S_ATTR_STRIP_STATIC_SYMS |
-                                   S_ATTR_NO_DEAD_STRIP | S_ATTR_LIVE_SUPPORT;
-  if ((input->flags ^ flags) & strictFlags)
-    error("Cannot merge section " + input->name + " (flags=0x" +
-          to_hexString(input->flags) + ") into " + name + " (flags=0x" +
-          to_hexString(flags) + "): strict flags differ");
+void ConcatOutputSection::finalizeFlags(InputSection *input) {
 
-  // Negate pure instruction presence if any section isn't pure.
-  uint32_t pureMask = ~S_ATTR_PURE_INSTRUCTIONS | (input->flags & flags);
+  uint8_t inputType = input->flags & SECTION_TYPE;
+  uint32_t adjusted = S_REGULAR;
+  switch (inputType) {
+  default /*type-unspec'ed*/:
+    if (input->segname == segment_names::data &&
+        (input->name == section_names::objcClassList ||
+         input->name == section_names::objcCatList ||
+         input->name == section_names::objcNonLazyClassList ||
+         input->name == section_names::objcNonLazyCatList ||
+         input->name == section_names::objSuperrefs))
+      adjusted = S_REGULAR | S_ATTR_NO_DEAD_STRIP;
+    else if (input->segname == segment_names::data &&
+             input->name == section_names::objcSelfrefs)
+      adjusted = S_LITERAL_POINTERS | S_ATTR_NO_DEAD_STRIP;
+    else if (input->segname == segment_names::objc)
+      adjusted = S_REGULAR | S_ATTR_NO_DEAD_STRIP;
+    else if (input->segname == segment_names::ld &&
+             input->name == section_names::compactUnwind)
+      adjusted = S_REGULAR | S_ATTR_DEBUG;
+    break;
+  case S_4BYTE_LITERALS:
+  case S_8BYTE_LITERALS:
+  case S_16BYTE_LITERALS:
+  case S_CSTRING_LITERALS:
+  case S_ZEROFILL:
+  case S_LAZY_SYMBOL_POINTERS:
+  case S_MOD_TERM_FUNC_POINTERS:
+  case S_THREAD_LOCAL_REGULAR:
+  case S_THREAD_LOCAL_ZEROFILL:
+  case S_THREAD_LOCAL_VARIABLES:
+  case S_THREAD_LOCAL_INIT_FUNCTION_POINTERS:
+  case S_THREAD_LOCAL_VARIABLE_POINTERS:
+    adjusted = inputType;
+    break;
+  case S_NON_LAZY_SYMBOL_POINTERS:
+    if (config->outputType != MH_KEXT_BUNDLE &&
+        !(config->outputType == MH_EXECUTE && config->isPic))
+      adjusted = S_NON_LAZY_SYMBOL_POINTERS;
+    break;
+  case S_SYMBOL_STUBS:
+    adjusted =
+        S_SYMBOL_STUBS | S_ATTR_SOME_INSTRUCTIONS | S_ATTR_PURE_INSTRUCTIONS;
+    if (!input->relocs.empty())
+      adjusted |= S_ATTR_LOC_RELOC;
+    break;
+  }
 
-  // Merge the rest
-  flags |= input->flags;
-  flags &= pureMask;
+  flags |= adjusted;
 }
diff --git a/lld/MachO/InputSection.h b/lld/MachO/InputSection.h
--- a/lld/MachO/InputSection.h
+++ b/lld/MachO/InputSection.h
@@ -181,6 +181,7 @@
 constexpr const char bitcodeBundle[] = "__bundle";
 constexpr const char cString[] = "__cstring";
 constexpr const char cfString[] = "__cfstring";
+constexpr const char classSect[] = "__class";
 constexpr const char codeSignature[] = "__code_signature";
 constexpr const char common[] = "__common";
 constexpr const char compactUnwind[] = "__compact_unwind";
@@ -207,6 +208,8 @@
 constexpr const char objcNonLazyCatList[] = "__objc_nlcatlist";
 constexpr const char objcNonLazyClassList[] = "__objc_nlclslist";
 constexpr const char objcProtoList[] = "__objc_protolist";
+constexpr const char objcSelfrefs[] = "__objc_selrefs";
+constexpr const char objSuperrefs[] = "__objc_superrefs";
 constexpr const char pageZero[] = "__pagezero";
 constexpr const char pointers[] = "__pointers";
 constexpr const char rebase[] = "__rebase";
diff --git a/lld/MachO/OutputSegment.h b/lld/MachO/OutputSegment.h
--- a/lld/MachO/OutputSegment.h
+++ b/lld/MachO/OutputSegment.h
@@ -28,6 +28,7 @@
 constexpr const char ld[] = "__LD"; // output only with -r
 constexpr const char linkEdit[] = "__LINKEDIT";
 constexpr const char llvm[] = "__LLVM";
+constexpr const char objc[] = "__OBJC";
 constexpr const char pageZero[] = "__PAGEZERO";
 constexpr const char textExec[] = "__TEXT_EXEC";
 constexpr const char text[] = "__TEXT";