diff --git a/compiler-rt/lib/hwasan/hwasan_report.cc b/compiler-rt/lib/hwasan/hwasan_report.cc
index 60eb5c1a498b..4c6c8b931bfb 100644
--- a/compiler-rt/lib/hwasan/hwasan_report.cc
+++ b/compiler-rt/lib/hwasan/hwasan_report.cc
@@ -46,19 +46,21 @@ class Decorator: public __sanitizer::SanitizerCommonDecorator {
   const char *Thread() { return Green(); }
 };
 
-bool FindHeapAllocation(HeapAllocationsRingBuffer *rb,
+// Returns the index of the rb element that matches tagged_addr (plus one),
+// or zero if found nothing.
+uptr FindHeapAllocation(HeapAllocationsRingBuffer *rb,
                         uptr tagged_addr,
                         HeapAllocationRecord *har) {
-  if (!rb) return false;
+  if (!rb) return 0;
   for (uptr i = 0, size = rb->size(); i < size; i++) {
     auto h = (*rb)[i];
     if (h.tagged_addr <= tagged_addr &&
         h.tagged_addr + h.requested_size > tagged_addr) {
       *har = h;
-      return true;
+      return i + 1;
     }
   }
-  return false;
+  return 0;
 }
 
 void PrintAddressDescription(uptr tagged_addr, uptr access_size) {
@@ -110,7 +112,7 @@ void PrintAddressDescription(uptr tagged_addr, uptr access_size) {
   Thread::VisitAllLiveThreads([&](Thread *t) {
     // Scan all threads' ring buffers to find if it's a heap-use-after-free.
     HeapAllocationRecord har;
-    if (FindHeapAllocation(t->heap_allocations(), tagged_addr, &har)) {
+    if (uptr D = FindHeapAllocation(t->heap_allocations(), tagged_addr, &har)) {
       Printf("%s", d.Location());
       Printf("%p is located %zd bytes inside of %zd-byte region [%p,%p)\n",
              untagged_addr, untagged_addr - UntagAddr(har.tagged_addr),
@@ -127,6 +129,11 @@ void PrintAddressDescription(uptr tagged_addr, uptr access_size) {
       GetStackTraceFromId(har.alloc_context_id).Print();
       t->Announce();
 
+      // Print a developer note: the index of this heap object
+      // in the thread's deallocation ring buffer.
+      Printf("hwasan_dev_note_heap_rb_distance: %zd %zd\n", D,
+             flags()->heap_history_size);
+
       num_descriptions_printed++;
     }
 
diff --git a/compiler-rt/test/hwasan/TestCases/uaf_with_rb_distance.c b/compiler-rt/test/hwasan/TestCases/uaf_with_rb_distance.c
new file mode 100644
index 000000000000..25aae5256c41
--- /dev/null
+++ b/compiler-rt/test/hwasan/TestCases/uaf_with_rb_distance.c
@@ -0,0 +1,27 @@
+// Checks how we print the developer note "hwasan_dev_note_heap_rb_distance".
+// RUN: %clang_hwasan %s -o %t
+// RUN: not %run %t 10 2>&1 | FileCheck %s --check-prefix=D10
+// RUN: not %run %t 42 2>&1 | FileCheck %s --check-prefix=D42
+
+// REQUIRES: stable-runtime
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <sanitizer/hwasan_interface.h>
+
+
+void *p[100];
+
+int main(int argc, char **argv) {
+  __hwasan_enable_allocator_tagging();
+  int distance = argc >= 2 ? atoi(argv[1]) : 1;
+  for (int i = 0; i < 100; i++)
+    p[i] = malloc(i);
+  for (int i = 0; i < 100; i++)
+    free(p[i]);
+
+  *(int*)p[distance] = 0;
+}
+
+// D10: hwasan_dev_note_heap_rb_distance: 90 1023
+// D42: hwasan_dev_note_heap_rb_distance: 58 1023