diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -473,7 +473,7 @@
   }
 
   if (path.endswith_insensitive(".lib"))
-    visitedLibs.insert(std::string(sys::path::filename(path)));
+    visitedLibs.insert(std::string(sys::path::filename(path).lower()));
   return path;
 }
 
diff --git a/lld/test/COFF/visitedlibs.test b/lld/test/COFF/visitedlibs.test
new file mode 100644
--- /dev/null
+++ b/lld/test/COFF/visitedlibs.test
@@ -0,0 +1,10 @@
+# RUN: rm -rf %t && mkdir -p %t
+# RUN: cp %S/Inputs/hello64.obj %t
+# RUN: cp %S/Inputs/std64.lib %t/STD64.lib
+
+# RUN: lld-link %t/STD64.lib /out:%t.exe /entry:main \
+# RUN:   /subsystem:console %t/hello64.obj /defaultlib:STD64.lib \
+# RUN:   /verbose 2>&1 | FileCheck %s
+
+CHECK: Reading {{.*}}/STD64.lib
+CHECK-NOT: could not open 'STD64.lib'