Index: include/llvm/IR/Metadata.h
===================================================================
--- include/llvm/IR/Metadata.h
+++ include/llvm/IR/Metadata.h
@@ -1278,6 +1278,11 @@
     if (!Use)
       return;
     *Use = MD;
+
+    if (*Use)
+      MetadataTracking::track(*Use);
+
+    // Equivalent to MetadataTracking::untrack
     Use = nullptr;
   }
 };
Index: test/ThinLTO/X86/Inputs/lazy-load-temporaries-cleanup.b.ll
===================================================================
--- /dev/null
+++ test/ThinLTO/X86/Inputs/lazy-load-temporaries-cleanup.b.ll
@@ -0,0 +1,11 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void  @patatino() {
+  ret void
+}
+
+!named = !{!0}
+
+!0  =  distinct !{!1, i8 0}
+!1  = !{i8 1}
Index: test/ThinLTO/X86/lazy-load-temporaries-cleanup.ll
===================================================================
--- /dev/null
+++ test/ThinLTO/X86/lazy-load-temporaries-cleanup.ll
@@ -0,0 +1,3 @@
+; This test ensures that metadata temporaries are properly tracked, then cleaned up
+
+; RUN: opt -module-summary -bitcode-mdindex-threshold=0 %S/Inputs/lazy-load-temporaries-cleanup.b.ll | llvm-dis -materialize-metadata -set-importing
Index: tools/llvm-dis/llvm-dis.cpp
===================================================================
--- tools/llvm-dis/llvm-dis.cpp
+++ tools/llvm-dis/llvm-dis.cpp
@@ -51,6 +51,9 @@
 DontPrint("disable-output", cl::desc("Don't output the .ll file"), cl::Hidden);
 
 static cl::opt<bool>
+SetImporting("set-importing", cl::desc("Set lazy loading to pretend to import a module"), cl::Hidden);
+
+static cl::opt<bool>
 ShowAnnotations("show-annotations",
                 cl::desc("Add informational comments to the .ll file"));
 
@@ -144,7 +147,7 @@
       ExitOnErr(errorOrToExpected(MemoryBuffer::getFileOrSTDIN(InputFilename)));
   std::unique_ptr<Module> M =
       ExitOnErr(getOwningLazyBitcodeModule(std::move(MB), Context,
-                                           /*ShouldLazyLoadMetadata=*/true));
+                                           /*ShouldLazyLoadMetadata=*/true, SetImporting));
   if (MaterializeMetadata)
     ExitOnErr(M->materializeMetadata());
   else