diff --git a/lld/MachO/ICF.cpp b/lld/MachO/ICF.cpp
--- a/lld/MachO/ICF.cpp
+++ b/lld/MachO/ICF.cpp
@@ -414,25 +414,30 @@
   std::vector<ConcatInputSection *> foldable;
   uint64_t icfUniqueID = inputSections.size();
   for (ConcatInputSection *isec : inputSections) {
-    bool isFoldableWithAddendsRemoved =
-        isCfStringSection(isec) || isClassRefsSection(isec);
+    bool isFoldableWithAddendsRemoved = isCfStringSection(isec) ||
+                                        isClassRefsSection(isec) ||
+                                        isSelRefsSection(isec);
+    // NOTE: __objc_selrefs is typically marked as no_dead_strip by MC, but we
+    // can still fold it.
+    bool hasFoldableFlags = (isSelRefsSection(isec) ||
+                             sectionType(isec->getFlags()) == MachO::S_REGULAR);
     // FIXME: consider non-code __text sections as foldable?
     bool isFoldable = (!onlyCfStrings || isCfStringSection(isec)) &&
-                      (isCodeSection(isec) || isGccExceptTabSection(isec) ||
-                       isFoldableWithAddendsRemoved) &&
+                      (isCodeSection(isec) || isFoldableWithAddendsRemoved ||
+                       isGccExceptTabSection(isec)) &&
                       !isec->keepUnique && !isec->shouldOmitFromOutput() &&
-                      sectionType(isec->getFlags()) == MachO::S_REGULAR;
+                      hasFoldableFlags;
     if (isFoldable) {
       foldable.push_back(isec);
       for (Defined *d : isec->symbols)
         if (d->unwindEntry)
           foldable.push_back(d->unwindEntry);
 
-      // __cfstring has embedded addends that foil ICF's hashing / equality
+      // Some sections have embedded addends that foil ICF's hashing / equality
       // checks. (We can ignore embedded addends when doing ICF because the same
       // information gets recorded in our Reloc structs.) We therefore create a
-      // mutable copy of the CFString and zero out the embedded addends before
-      // performing any hashing / equality checks.
+      // mutable copy of the the section data and zero out the embedded addends
+      // before performing any hashing / equality checks.
       if (isFoldableWithAddendsRemoved) {
         // We have to do this copying serially as the BumpPtrAllocator is not
         // thread-safe. FIXME: Make a thread-safe allocator.
@@ -443,7 +448,7 @@
         isec->data = copy;
       }
     } else if (!isEhFrameSection(isec)) {
-      // EH frames are gathered as foldable from unwindEntry above; give a
+      // EH frames are gathered as foldables from unwindEntry above; give a
       // unique ID to everything else.
       isec->icfEqClass[0] = ++icfUniqueID;
     }
diff --git a/lld/MachO/InputFiles.cpp b/lld/MachO/InputFiles.cpp
--- a/lld/MachO/InputFiles.cpp
+++ b/lld/MachO/InputFiles.cpp
@@ -274,6 +274,9 @@
 
   if (name == section_names::objcClassRefs && segname == segment_names::data)
     return target->wordSize;
+
+  if (name == section_names::objcSelrefs && segname == segment_names::data)
+    return target->wordSize;
   return {};
 }
 
diff --git a/lld/MachO/InputSection.h b/lld/MachO/InputSection.h
--- a/lld/MachO/InputSection.h
+++ b/lld/MachO/InputSection.h
@@ -285,6 +285,7 @@
 bool isCodeSection(const InputSection *);
 bool isCfStringSection(const InputSection *);
 bool isClassRefsSection(const InputSection *);
+bool isSelRefsSection(const InputSection *);
 bool isEhFrameSection(const InputSection *);
 bool isGccExceptTabSection(const InputSection *);
 
diff --git a/lld/MachO/InputSection.cpp b/lld/MachO/InputSection.cpp
--- a/lld/MachO/InputSection.cpp
+++ b/lld/MachO/InputSection.cpp
@@ -332,6 +332,11 @@
          isec->getSegName() == segment_names::data;
 }
 
+bool macho::isSelRefsSection(const InputSection *isec) {
+  return isec->getName() == section_names::objcSelrefs &&
+         isec->getSegName() == segment_names::data;
+}
+
 bool macho::isEhFrameSection(const InputSection *isec) {
   return isec->getName() == section_names::ehFrame &&
          isec->getSegName() == segment_names::text;
diff --git a/lld/test/MachO/objc-selrefs.s b/lld/test/MachO/objc-selrefs.s
--- a/lld/test/MachO/objc-selrefs.s
+++ b/lld/test/MachO/objc-selrefs.s
@@ -1,11 +1,21 @@
 # REQUIRES: aarch64
 # RUN: rm -rf %t; split-file %s %t
 
-# RUN: llvm-mc -filetype=obj -triple=arm64-apple-darwin %t/existing.s -o %t/existing.o
-# RUN: llvm-mc -filetype=obj -triple=arm64-apple-darwin %t/main.s -o %t/main.o
+# RUN: llvm-mc -filetype=obj -triple=arm64-apple-darwin %t/explicit-selrefs-1.s -o %t/explicit-selrefs-1.o
+# RUN: llvm-mc -filetype=obj -triple=arm64-apple-darwin %t/explicit-selrefs-2.s -o %t/explicit-selrefs-2.o
+# RUN: llvm-mc -filetype=obj -triple=arm64-apple-darwin %t/implicit-selrefs.s -o %t/implicit-selrefs.o
 
-# RUN: %lld -arch arm64 -lSystem -o %t/out %t/existing.o %t/main.o
-# RUN: llvm-otool -vs __DATA __objc_selrefs %t/out | FileCheck %s --check-prefix=SELREFS
+# RUN: %lld -dylib -arch arm64 -lSystem -o %t/explicit-only-no-icf \
+# RUN:   %t/explicit-selrefs-1.o %t/explicit-selrefs-2.o
+# RUN: llvm-otool -vs __DATA __objc_selrefs %t/explicit-only-no-icf | \
+# RUN:   FileCheck %s --check-prefix=EXPLICIT-NO-ICF
+
+## NOTE: ld64 always dedups the selrefs unconditionally, but we only do it when
+## ICF is enabled.
+# RUN: %lld -dylib -arch arm64 -lSystem -o %t/explicit-only-with-icf \
+# RUN:   %t/explicit-selrefs-1.o %t/explicit-selrefs-2.o
+# RUN: llvm-otool -vs __DATA __objc_selrefs %t/explicit-only-with-icf \
+# RUN:   | FileCheck %s --check-prefix=EXPLICIT-WITH-ICF
 
 # SELREFS: Contents of (__DATA,__objc_selrefs) section
 # SELREFS-NEXT: __TEXT:__objc_methname:foo
@@ -14,18 +24,30 @@
 # SELREFS-NEXT: __TEXT:__objc_methname:length
 # SELREFS-EMPTY:
 
-# RUN: %lld -arch arm64 -lSystem -o %t/out %t/existing.o %t/main.o --deduplicate-literals
-# RUN: llvm-otool -vs __DATA __objc_selrefs %t/out | FileCheck %s --check-prefix=DEDUP
+## We don't yet support dedup'ing implicitly-defined selrefs.
+# RUN: %lld -dylib -arch arm64 -lSystem --icf=all -o %t/explicit-and-implicit \
+# RUN:   %t/explicit-selrefs-1.o %t/explicit-selrefs-2.o %t/implicit-selrefs.o
+# RUN: llvm-otool -vs __DATA __objc_selrefs %t/explicit-and-implicit \
+# RUN:   | FileCheck %s --check-prefix=EXPLICIT-AND-IMPLICIT
+
+# EXPLICIT-NO-ICF:       Contents of (__DATA,__objc_selrefs) section
+# EXPLICIT-NO-ICF-NEXT:  __TEXT:__objc_methname:foo
+# EXPLICIT-NO-ICF-NEXT:  __TEXT:__objc_methname:bar
+# EXPLICIT-NO-ICF-NEXT:  __TEXT:__objc_methname:bar
+# EXPLICIT-NO-ICF-NEXT:  __TEXT:__objc_methname:foo
+
+# EXPLICIT-WITH-ICF:      Contents of (__DATA,__objc_selrefs) section
+# EXPLICIT-WITH-ICF-NEXT: __TEXT:__objc_methname:foo
+# EXPLICIT-WITH-ICF-NEXT: __TEXT:__objc_methname:bar
 
-# DEDUP: Contents of (__DATA,__objc_selrefs) section
-# DEDUP-NEXT: __TEXT:__objc_methname:foo
-# DEDUP-NEXT: __TEXT:__objc_methname:bar
+# EXPLICIT-AND-IMPLICIT:      Contents of (__DATA,__objc_selrefs) section
+# EXPLICIT-AND-IMPLICIT-NEXT: __TEXT:__objc_methname:foo
+# EXPLICIT-AND-IMPLICIT-NEXT: __TEXT:__objc_methname:bar
 # NOTE: Ideally this wouldn't exist, but while it does it needs to point to the deduplicated string
-# DEDUP-NEXT: __TEXT:__objc_methname:foo
-# DEDUP-NEXT: __TEXT:__objc_methname:length
-# DEDUP-EMPTY:
+# EXPLICIT-AND-IMPLICIT-NEXT: __TEXT:__objc_methname:foo
+# EXPLICIT-AND-IMPLICIT-NEXT: __TEXT:__objc_methname:length
 
-#--- existing.s
+#--- explicit-selrefs-1.s
 .section  __TEXT,__objc_methname,cstring_literals
 lselref1:
   .asciz  "foo"
@@ -34,17 +56,28 @@
 
 .section  __DATA,__objc_selrefs,literal_pointers,no_dead_strip
 .p2align  3
-.quad lselref1
-.quad lselref2
+  .quad lselref1
+  .quad lselref2
+  .quad lselref2
+
+#--- explicit-selrefs-2.s
+.section  __TEXT,__objc_methname,cstring_literals
+lselref1:
+  .asciz  "foo"
+
+.section  __DATA,__objc_selrefs,literal_pointers,no_dead_strip
+.p2align  3
+  .quad lselref1
 
-#--- main.s
+#--- implicit-selrefs.s
 .text
 .globl _objc_msgSend
+.p2align 2
 _objc_msgSend:
   ret
 
-.globl _main
-_main:
-  bl  _objc_msgSend$length
-  bl  _objc_msgSend$foo
+.p2align 2
+_sender:
+  bl _objc_msgSend$length
+  bl _objc_msgSend$foo
   ret