Index: ELF/Driver.h
===================================================================
--- ELF/Driver.h
+++ ELF/Driver.h
@@ -39,9 +39,6 @@
   // True if we are in --whole-archive and --no-whole-archive.
   bool InWholeArchive = false;
 
-  // True if we are in --start-lib and --end-lib.
-  bool InLib = false;
-
   // True if we are in -format=binary and -format=elf.
   bool InBinary = false;
 
Index: ELF/Driver.cpp
===================================================================
--- ELF/Driver.cpp
+++ ELF/Driver.cpp
@@ -236,7 +236,7 @@
     return;
   case file_magic::bitcode:
   case file_magic::elf_relocatable:
-    if (InLib)
+    if (InputFile::IsInLib)
       Files.push_back(make<LazyObjFile>(MBRef, "", 0));
     else
       Files.push_back(createObjectFile(MBRef));
@@ -990,10 +990,12 @@
       ++InputFile::NextGroupId;
       break;
     case OPT_start_lib:
-      InLib = true;
+      InputFile::IsInLib = true;
       break;
     case OPT_end_lib:
-      InLib = false;
+      InputFile::IsInLib = false;
+      if (!InputFile::IsInGroup)
+        ++InputFile::NextGroupId;
       break;
     }
   }
Index: ELF/InputFiles.h
===================================================================
--- ELF/InputFiles.h
+++ ELF/InputFiles.h
@@ -113,13 +113,16 @@
   bool JustSymbols = false;
 
   // GroupId is used for --warn-backrefs which is an optional error
-  // checking feature. All files within the same --{start,end}-group
-  // get the same group ID. Otherwise, each file gets a new group
-  // ID. For more info, see checkDependency() in SymbolTable.cpp.
+  // checking feature. All files within the same --{start,end}-group or
+  // --{start,end}-lib get the same group ID. Otherwise, each file gets a new
+  // group ID. For more info, see checkDependency() in SymbolTable.cpp.
   uint32_t GroupId;
   static bool IsInGroup;
   static uint32_t NextGroupId;
 
+  // True if we are in --start-lib and --end-lib.
+  static bool IsInLib;
+
 protected:
   InputFile(Kind K, MemoryBufferRef M);
   std::vector<InputSectionBase *> Sections;
Index: ELF/InputFiles.cpp
===================================================================
--- ELF/InputFiles.cpp
+++ ELF/InputFiles.cpp
@@ -40,6 +40,7 @@
 
 bool InputFile::IsInGroup;
 uint32_t InputFile::NextGroupId;
+bool InputFile::IsInLib;
 std::vector<BinaryFile *> elf::BinaryFiles;
 std::vector<BitcodeFile *> elf::BitcodeFiles;
 std::vector<InputFile *> elf::ObjectFiles;
@@ -51,7 +52,7 @@
     : MB(M), GroupId(NextGroupId), FileKind(K) {
   // All files within the same --{start,end}-group get the same group ID.
   // Otherwise, a new file will get a new group ID.
-  if (!IsInGroup)
+  if (!IsInGroup && !IsInLib)
     ++NextGroupId;
 }
 
Index: test/ELF/warn-backrefs.s
===================================================================
--- test/ELF/warn-backrefs.s
+++ test/ELF/warn-backrefs.s
@@ -35,6 +35,10 @@
 # RUN: not ld.lld --fatal-warnings --end-group 2>&1 | FileCheck -check-prefix=END %s
 # END: stray --end-group
 
+# RUN: echo ".globl bar; bar:" | llvm-mc -filetype=obj -triple=x86_64-unknown-linux - -o %t3.o
+# RUN: echo ".globl foo; foo: call bar" | llvm-mc -filetype=obj -triple=x86_64-unknown-linux - -o %t4.o
+# RUN: ld.lld --fatal-warnings --warn-backrefs %t1.o --start-lib %t3.o %t4.o --end-lib
+
 .globl _start, foo
 _start:
   call foo