diff --git a/src/spectator/harness.cr b/src/spectator/harness.cr
index ebbf5db..88873e3 100644
--- a/src/spectator/harness.cr
+++ b/src/spectator/harness.cr
@@ -1,3 +1,5 @@
+require "./mocks/registry"
+
 module Spectator
   # Helper class that acts as a gateway between example code and the test framework.
   # Every example must be invoked by passing it to `#run`.
@@ -25,7 +27,8 @@ module Spectator
     # The *example* argument will be the example to run.
     # The result returned from `Example#run` will be returned.
     def self.run(example : Example) : Result
-      @@current = new(example)
+      @@current = harness = new(example)
+      harness.mocks.prepare(example.group.context)
       example.run
     ensure
       @@current = nil
@@ -34,6 +37,8 @@ module Spectator
     # Retrieves the current running example.
     getter example : Example
 
+    getter mocks = Mocks::Registry.new
+
     # Retrieves the group for the current running example.
     def group
       example.group
@@ -51,10 +56,6 @@ module Spectator
       @reporter.expectations
     end
 
-    def double(id)
-      example.group.double(id, example.sample_values)
-    end
-
     # Creates a new harness.
     # The example the harness is for should be passed in.
     private def initialize(@example)
diff --git a/src/spectator/matchers/receive_arguments_matcher.cr b/src/spectator/matchers/receive_arguments_matcher.cr
index 0110d53..bc729db 100644
--- a/src/spectator/matchers/receive_arguments_matcher.cr
+++ b/src/spectator/matchers/receive_arguments_matcher.cr
@@ -14,7 +14,7 @@ module Spectator::Matchers
     end
 
     def match?(actual : TestExpression(T)) : Bool forall T
-      calls = Mocks::Registry.calls_for(actual.value, @expected.value).select { |call| @args === call.args }
+      calls = Harness.current.mocks.calls_for(actual.value, @expected.value).select { |call| @args === call.args }
       if (range = @range)
         range.includes?(calls.size)
       else
@@ -28,7 +28,7 @@ module Spectator::Matchers
     end
 
     def values(actual : TestExpression(T)) forall T
-      calls = Mocks::Registry.calls_for(actual.value, @expected.value).select { |call| @args === call.args }
+      calls = Harness.current.mocks.calls_for(actual.value, @expected.value).select { |call| @args === call.args }
       range = @range
       {
         expected: "#{range ? "#{humanize_range(range)} time(s)" : "At least once"} with #{@args}",
diff --git a/src/spectator/matchers/receive_matcher.cr b/src/spectator/matchers/receive_matcher.cr
index 489f453..376047a 100644
--- a/src/spectator/matchers/receive_matcher.cr
+++ b/src/spectator/matchers/receive_matcher.cr
@@ -14,7 +14,7 @@ module Spectator::Matchers
     end
 
     def match?(actual : TestExpression(T)) : Bool forall T
-      calls = Mocks::Registry.calls_for(actual.value, @expected.value)
+      calls = Harness.current.mocks.calls_for(actual.value, @expected.value)
       if (range = @range)
         range.includes?(calls.size)
       else
@@ -28,7 +28,7 @@ module Spectator::Matchers
     end
 
     def values(actual : TestExpression(T)) forall T
-      calls = Mocks::Registry.calls_for(actual.value, @expected.value)
+      calls = Harness.current.mocks.calls_for(actual.value, @expected.value)
       range = @range
       {
         expected: "#{range ? "#{humanize_range(range)} time(s)" : "At least once"} with any arguments",
diff --git a/src/spectator/mocks/allow.cr b/src/spectator/mocks/allow.cr
index 00ecc99..1479e69 100644
--- a/src/spectator/mocks/allow.cr
+++ b/src/spectator/mocks/allow.cr
@@ -6,7 +6,7 @@ module Spectator::Mocks
     end
 
     def to(stub : MethodStub) : Nil
-      Registry.add_stub(@mock, stub)
+      Harness.current.mocks.add_stub(@mock, stub)
     end
   end
 end
diff --git a/src/spectator/mocks/double.cr b/src/spectator/mocks/double.cr
index bceaeff..e714042 100644
--- a/src/spectator/mocks/double.cr
+++ b/src/spectator/mocks/double.cr
@@ -36,8 +36,8 @@ module Spectator::Mocks
       def {{name}}({{params.splat}}){% if definition.is_a?(TypeDeclaration) %} : {{definition.type}}{% end %}
         %args = ::Spectator::Mocks::GenericArguments.create({{args.splat}})
         %call = ::Spectator::Mocks::GenericMethodCall.new({{name.symbolize}}, %args)
-        ::Spectator::Mocks::Registry.record_call(self, %call)
-        if (%stub = ::Spectator::Mocks::Registry.find_stub(self, %call))
+        ::Spectator::Harness.current.mocks.record_call(self, %call)
+        if (%stub = ::Spectator::Harness.current.mocks.find_stub(self, %call))
           %stub.call!(%args, typeof(%method({{args.splat}})))
         else
           %method({{args.splat}})
@@ -47,8 +47,8 @@ module Spectator::Mocks
       def {{name}}({{params.splat}}){% if definition.is_a?(TypeDeclaration) %} : {{definition.type}}{% end %}
         %args = ::Spectator::Mocks::GenericArguments.create({{args.splat}})
         %call = ::Spectator::Mocks::GenericMethodCall.new({{name.symbolize}}, %args)
-        ::Spectator::Mocks::Registry.record_call(self, %call)
-        if (%stub = ::Spectator::Mocks::Registry.find_stub(self, %call))
+        ::Spectator::Harness.current.mocks.record_call(self, %call)
+        if (%stub = ::Spectator::Harness.current.mocks.find_stub(self, %call))
           %stub.call!(%args, typeof(%method({{args.splat}}) { |*%ya| yield *%ya }))
         else
           %method({{args.splat}}) do |*%yield_args|
diff --git a/src/spectator/mocks/stubs.cr b/src/spectator/mocks/stubs.cr
index f4f633f..ed7e1b1 100644
--- a/src/spectator/mocks/stubs.cr
+++ b/src/spectator/mocks/stubs.cr
@@ -36,8 +36,8 @@ module Spectator::Mocks
       def {{name}}({{params.splat}}){% if definition.is_a?(TypeDeclaration) %} : {{definition.type}}{% end %}
         %args = ::Spectator::Mocks::GenericArguments.create({{args.splat}})
         %call = ::Spectator::Mocks::GenericMethodCall.new({{name.symbolize}}, %args)
-        ::Spectator::Mocks::Registry.record_call(self, %call)
-        if (%stub = ::Spectator::Mocks::Registry.find_stub(self, %call))
+        ::Spectator::Harness.current.mocks.record_call(self, %call)
+        if (%stub = ::Spectator::Harness.current.mocks.find_stub(self, %call))
           %stub.call!(%args, typeof({{original}}({{args.splat}})))
         else
           {{original}}({{args.splat}})
@@ -47,8 +47,8 @@ module Spectator::Mocks
       def {{name}}({{params.splat}}){% if definition.is_a?(TypeDeclaration) %} : {{definition.type}}{% end %}
         %args = ::Spectator::Mocks::GenericArguments.create({{args.splat}})
         %call = ::Spectator::Mocks::GenericMethodCall.new({{name.symbolize}}, %args)
-        ::Spectator::Mocks::Registry.record_call(self, %call)
-        if (%stub = ::Spectator::Mocks::Registry.find_stub(self, %call))
+        ::Spectator::Harness.current.mocks.record_call(self, %call)
+        if (%stub = ::Spectator::Harness.current.mocks.find_stub(self, %call))
           %stub.call!(%args, typeof({{original}}({{args.splat}}) { |*%ya| yield *%ya }))
         else
           {{original}}({{args.splat}}) do |*%yield_args|
diff --git a/src/spectator/runnable_example.cr b/src/spectator/runnable_example.cr
index c5c0b5b..d981689 100644
--- a/src/spectator/runnable_example.cr
+++ b/src/spectator/runnable_example.cr
@@ -7,11 +7,9 @@ module Spectator
     # Runs the example, hooks, and captures the result
     # and translates to a usable result.
     def run_impl : Result
-      Mocks.run(group.context) do
-        result = capture_result
-        expectations = Harness.current.expectations
-        translate_result(result, expectations)
-      end
+      result = capture_result
+      expectations = Harness.current.expectations
+      translate_result(result, expectations)
     end
 
     # Runs all hooks and the example code.