Index: lld/COFF/InputFiles.cpp
===================================================================
--- lld/COFF/InputFiles.cpp
+++ lld/COFF/InputFiles.cpp
@@ -905,8 +905,9 @@
   // filename unique.
   MemoryBufferRef mbref(
       mb.getBuffer(),
-      saver.save(archiveName + path +
-                 (archiveName.empty() ? "" : utostr(offsetInArchive))));
+      saver.save(archiveName.empty() ? path
+                                     : archiveName + sys::path::filename(path) +
+                                           utostr(offsetInArchive)));
 
   obj = check(lto::InputFile::create(mbref));
 }
Index: lld/ELF/InputFiles.cpp
===================================================================
--- lld/ELF/InputFiles.cpp
+++ lld/ELF/InputFiles.cpp
@@ -1418,10 +1418,11 @@
   // into consideration at LTO time (which very likely causes undefined
   // symbols later in the link stage). So we append file offset to make
   // filename unique.
-  StringRef name = archiveName.empty()
-                       ? saver.save(path)
-                       : saver.save(archiveName + "(" + path + " at " +
-                                    utostr(offsetInArchive) + ")");
+  StringRef name =
+      archiveName.empty()
+          ? saver.save(path)
+          : saver.save(archiveName + "(" + path::filename(path) + " at " +
+                       utostr(offsetInArchive) + ")");
   MemoryBufferRef mbref(mb.getBuffer(), name);
 
   obj = CHECK(lto::InputFile::create(mbref), this);
Index: lld/test/COFF/thinlto.ll
===================================================================
--- lld/test/COFF/thinlto.ll
+++ lld/test/COFF/thinlto.ll
@@ -6,6 +6,11 @@
 ; RUN: lld-link /lldsavetemps /out:%T/thinlto/main.exe /entry:main /subsystem:console %T/thinlto/main.obj %T/thinlto/foo.obj
 ; RUN: llvm-nm %T/thinlto/main.exe1.lto.obj | FileCheck %s
 
+; This command will store full path to foo.obj in the archive %t.lib
+; Check that /lldsavetemps is still usable in such case.
+; RUN: lld-link /lib %T/thinlto/foo.obj /out:%t.lib
+; RUN: lld-link /lldsavetemps /out:%t.exe /entry:main /subsystem:console %T/thinlto/main.obj %t.lib
+
 ; CHECK-NOT: U foo
 
 target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
Index: lld/test/ELF/lto/thinlto.ll
===================================================================
--- lld/test/ELF/lto/thinlto.ll
+++ lld/test/ELF/lto/thinlto.ll
@@ -21,6 +21,10 @@
 ; RUN: llvm-nm %t31.lto.o | FileCheck %s --check-prefix=NM1
 ; RUN: llvm-nm %t32.lto.o | FileCheck %s --check-prefix=NM2
 
+; Check that -save-temps is usable with thin archives
+; RUN: llvm-ar rcsT %t2.a %t2.o
+; RUN: ld.lld -save-temps %t1.o %t2.a -o - > /dev/null
+
 ; NM1: T f
 ; NM2: T g