diff --git a/benchmark/CMakeLists.txt b/benchmark/CMakeLists.txt
index 200b451407bc5..bd6280dc8995a 100644
--- a/benchmark/CMakeLists.txt
+++ b/benchmark/CMakeLists.txt
@@ -72,6 +72,7 @@ set(SWIFT_BENCH_MODULES
     single-source/DictionaryGroup
     single-source/DictionaryKeysContains
     single-source/DictionaryLiteral
+    single-source/DictionaryOfAnyHashableStrings
     single-source/DictionaryRemove
     single-source/DictionarySubscriptDefault
     single-source/DictionarySwap
diff --git a/benchmark/single-source/DictionaryOfAnyHashableStrings.swift b/benchmark/single-source/DictionaryOfAnyHashableStrings.swift
new file mode 100644
index 0000000000000..fec3d52769944
--- /dev/null
+++ b/benchmark/single-source/DictionaryOfAnyHashableStrings.swift
@@ -0,0 +1,83 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import TestsUtils
+
+// This benchmark tests the performance of Dictionary<AnyHashable, Any> with
+// small ASCII String keys. Untyped NSDictionary values get imported as this
+// type, so it occurs relatively often in practice.
+
+public var DictionaryOfAnyHashableStrings = [
+  BenchmarkInfo(
+    name: "DictionaryOfAnyHashableStrings_insert",
+    runFunction: run_DictionaryOfAnyHashableStrings_insert,
+    tags: [.abstraction, .runtime, .cpubench],
+    setUpFunction: {
+      keys = buildKeys(500)
+    }
+  ),
+  BenchmarkInfo(
+    name: "DictionaryOfAnyHashableStrings_lookup",
+    runFunction: run_DictionaryOfAnyHashableStrings_lookup,
+    tags: [.abstraction, .runtime, .cpubench],
+    setUpFunction: {
+      keys = buildKeys(500)
+      workload = buildWorkload()
+    }
+  ),
+]
+
+var keys: [String] = []
+var workload: [AnyHashable: Any] = [:]
+
+func buildKeys(_ size: Int) -> [String] {
+  var result: [String] = []
+  let keyPrefixes = ["font", "bgcolor", "fgcolor", "blink", "marquee"]
+  for key in keyPrefixes {
+    for i in 0 ..< size {
+      result.append(key + "\(i)")
+    }
+  }
+  return result
+}
+
+func buildWorkload() -> [AnyHashable: Any] {
+  precondition(keys.count > 0)
+  var result: [AnyHashable: Any] = [:]
+  var i = 0
+  for key in keys {
+    result[key] = i
+    i += 1
+  }
+  return result
+}
+
+
+@inline(never)
+public func run_DictionaryOfAnyHashableStrings_insert(_ n: Int) {
+  precondition(keys.count > 0)
+  for _ in 0 ... n {
+    blackHole(buildWorkload())
+  }
+}
+
+@inline(never)
+public func run_DictionaryOfAnyHashableStrings_lookup(_ n: Int) {
+  precondition(workload.count > 0)
+  precondition(keys.count > 0)
+  for _ in 0 ... n {
+    for i in 0 ..< keys.count {
+      let key = keys[i]
+      CheckResults((workload[key] as! Int) == i)
+    }
+  }
+}
diff --git a/benchmark/utils/main.swift b/benchmark/utils/main.swift
index 22e15e9cf5d69..cac9c2f07b1a5 100644
--- a/benchmark/utils/main.swift
+++ b/benchmark/utils/main.swift
@@ -60,6 +60,7 @@ import DictionaryCopy
 import DictionaryGroup
 import DictionaryKeysContains
 import DictionaryLiteral
+import DictionaryOfAnyHashableStrings
 import DictionaryRemove
 import DictionarySubscriptDefault
 import DictionarySwap
@@ -226,6 +227,7 @@ registerBenchmark(DictionaryCopy)
 registerBenchmark(DictionaryGroup)
 registerBenchmark(DictionaryKeysContains)
 registerBenchmark(DictionaryLiteral)
+registerBenchmark(DictionaryOfAnyHashableStrings)
 registerBenchmark(DictionaryRemove)
 registerBenchmark(DictionarySubscriptDefault)
 registerBenchmark(DictionarySwap)