diff --git a/lld/MachO/ConcatOutputSection.cpp b/lld/MachO/ConcatOutputSection.cpp
--- a/lld/MachO/ConcatOutputSection.cpp
+++ b/lld/MachO/ConcatOutputSection.cpp
@@ -339,7 +339,7 @@
 void ConcatOutputSection::finalizeFlags(InputSection *input) {
   switch (sectionType(input->getFlags())) {
   default /*type-unspec'ed*/:
-    // FIXME: Add additional logics here when supporting emitting obj files.
+    // FIXME: Add additional logic here when supporting emitting obj files.
     break;
   case S_4BYTE_LITERALS:
   case S_8BYTE_LITERALS:
@@ -373,8 +373,5 @@
   auto newNames = config->sectionRenameMap.find(key);
   if (newNames != config->sectionRenameMap.end())
     return newNames->second;
-  auto newName = config->segmentRenameMap.find(key.first);
-  if (newName != config->segmentRenameMap.end())
-    return std::make_pair(newName->second, key.second);
   return key;
 }
diff --git a/lld/MachO/OutputSegment.cpp b/lld/MachO/OutputSegment.cpp
--- a/lld/MachO/OutputSegment.cpp
+++ b/lld/MachO/OutputSegment.cpp
@@ -153,7 +153,16 @@
 static DenseMap<StringRef, OutputSegment *> nameToOutputSegment;
 std::vector<OutputSegment *> macho::outputSegments;
 
+static StringRef maybeRenameSegment(StringRef name) {
+  auto newName = config->segmentRenameMap.find(name);
+  if (newName != config->segmentRenameMap.end())
+    return newName->second;
+  return name;
+}
+
 OutputSegment *macho::getOrCreateOutputSegment(StringRef name) {
+  name = maybeRenameSegment(name);
+
   OutputSegment *&segRef = nameToOutputSegment[name];
   if (segRef)
     return segRef;
diff --git a/lld/test/MachO/rename.s b/lld/test/MachO/rename.s
--- a/lld/test/MachO/rename.s
+++ b/lld/test/MachO/rename.s
@@ -71,8 +71,7 @@
 # SECTSEGYES-NEXT:    segname __TEXT
 # SECTSEGYES:      Section
 # SECTSEGYES-NEXT:   sectname __to_sect
-# SECTSEGYES-NEXT:    segname __TO_SECT
-## FIXME: ^ This should use __SEG like ld64 does.
+# SECTSEGYES-NEXT:    segname __SEG
 ## ...but rename_segment has no effect if it doesn't match the name after
 ## rename_section is applied.
 # RUN: %lld -dylib \