diff --git a/lld/ELF/InputFiles.h b/lld/ELF/InputFiles.h
--- a/lld/ELF/InputFiles.h
+++ b/lld/ELF/InputFiles.h
@@ -207,8 +207,8 @@
 
   void parse(bool ignoreComdats = false);
 
-  StringRef getShtGroupSignature(ArrayRef<Elf_Shdr> sections,
-                                 const Elf_Shdr &sec);
+  llvm::Optional<StringRef> getShtGroupSignature(ArrayRef<Elf_Shdr> sections,
+                                                 const Elf_Shdr &sec);
 
   Symbol &getSymbol(uint32_t symbolIndex) const {
     if (symbolIndex >= this->symbols.size())
diff --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp
--- a/lld/ELF/InputFiles.cpp
+++ b/lld/ELF/InputFiles.cpp
@@ -416,12 +416,13 @@
   initializeSymbols();
 }
 
-// Sections with SHT_GROUP and comdat bits define comdat section groups.
-// They are identified and deduplicated by group name. This function
-// returns a group name.
+// The sh_info field of a SHT_GROUP section contains the symbol table index of
+// the signature symbol. This function returns None if the signature is local,
+// or a group name otherwise.
 template <class ELFT>
-StringRef ObjFile<ELFT>::getShtGroupSignature(ArrayRef<Elf_Shdr> sections,
-                                              const Elf_Shdr &sec) {
+Optional<StringRef>
+ObjFile<ELFT>::getShtGroupSignature(ArrayRef<Elf_Shdr> sections,
+                                    const Elf_Shdr &sec) {
   typename ELFT::SymRange symbols = this->getELFSyms<ELFT>();
   if (sec.sh_info >= symbols.size())
     fatal(toString(this) + ": invalid symbol index");
@@ -437,6 +438,9 @@
   // a bug-compatibility.
   if (signature.empty() && sym.getType() == STT_SECTION)
     return getSectionName(sec);
+
+  if (sym.getBinding() == STB_LOCAL)
+    return None;
   return signature;
 }
 
@@ -607,7 +611,7 @@
     switch (sec.sh_type) {
     case SHT_GROUP: {
       // De-duplicate section groups by their signatures.
-      StringRef signature = getShtGroupSignature(objSections, sec);
+      Optional<StringRef> signature = getShtGroupSignature(objSections, sec);
       this->sections[i] = &InputSection::discarded;
 
       ArrayRef<Elf_Word> entries =
@@ -619,10 +623,11 @@
       if (flag && flag != GRP_COMDAT)
         fatal(toString(this) + ": unsupported SHT_GROUP format");
 
-      bool keepGroup =
-          (flag & GRP_COMDAT) == 0 || ignoreComdats ||
-          symtab->comdatGroups.try_emplace(CachedHashStringRef(signature), this)
-              .second;
+      bool keepGroup = (flag & GRP_COMDAT) == 0 || ignoreComdats ||
+                       !signature ||
+                       symtab->comdatGroups
+                           .try_emplace(CachedHashStringRef(*signature), this)
+                           .second;
       if (keepGroup) {
         if (config->relocatable)
           this->sections[i] = createInputSection(sec);
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -708,11 +708,13 @@
     return msg;
 
   // If the discarded section is a COMDAT.
-  StringRef signature = file->getShtGroupSignature(objSections, elfSec);
-  if (const InputFile *prevailing =
-          symtab->comdatGroups.lookup(CachedHashStringRef(signature)))
-    msg += "\n>>> section group signature: " + signature.str() +
-           "\n>>> prevailing definition is in " + toString(prevailing);
+  if (Optional<StringRef> signature =
+          file->getShtGroupSignature(objSections, elfSec)) {
+    if (const InputFile *prevailing =
+            symtab->comdatGroups.lookup(CachedHashStringRef(*signature)))
+      msg += "\n>>> section group signature: " + signature->str() +
+             "\n>>> prevailing definition is in " + toString(prevailing);
+  }
   return msg;
 }
 
diff --git a/lld/test/ELF/comdat-local.s b/lld/test/ELF/comdat-local.s
new file mode 100644
--- /dev/null
+++ b/lld/test/ELF/comdat-local.s
@@ -0,0 +1,24 @@
+# REQUIRES: x86
+## If the signature symbol of a group is local, suppress COMDAT deduplication.
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t.o
+# RUN: ld.lld %t.o %t.o -o %t
+# RUN: llvm-readelf -s -x .zero -x .comdat %t | FileCheck %s
+
+# CHECK:      NOTYPE LOCAL DEFAULT [[#A:]] zero
+# CHECK-NEXT: NOTYPE LOCAL DEFAULT [[#B:]] comdat
+# CHECK-NEXT: NOTYPE LOCAL DEFAULT [[#A]]  zero
+# CHECK-NEXT: NOTYPE LOCAL DEFAULT [[#B]]  comdat
+
+# CHECK:      Hex dump of section '.zero':
+# CHECK-NEXT: [[#%x,_:]] 0202
+# CHECK:      Hex dump of section '.comdat':
+# CHECK-NEXT: [[#%x,_:]] 0101
+
+.section .zero,"aG",@progbits,zero
+zero:
+  .byte 2
+
+.section .comdat,"aG",@progbits,comdat,comdat
+comdat:
+  .byte 1