diff --git a/src/spectator.cr b/src/spectator.cr
index 9ab920e..9e7f988 100644
--- a/src/spectator.cr
+++ b/src/spectator.cr
@@ -68,8 +68,11 @@ module Spectator
     # Silence default logger.
     ::Log.setup_from_env(default_level: :none)
 
-    # Build the spec and run it.
+    # Build the spec.
     spec = DSL::Builder.build
+
+    # Run the spec with mocks enabled.
+    Mocks.enable
     spec.run
   rescue ex
     # Re-enable logger for fatal error.
@@ -82,6 +85,8 @@ module Spectator
     # So we display a helpful error that could be reported and return non-zero.
     Log.fatal(exception: ex) { "Spectator encountered an unexpected error" }
     false
+  ensure
+    Mocks.disable
   end
 
   # Global configuration used by Spectator for running tests.
diff --git a/src/spectator/harness.cr b/src/spectator/harness.cr
index 1f9fa09..be60f40 100644
--- a/src/spectator/harness.cr
+++ b/src/spectator/harness.cr
@@ -136,11 +136,13 @@ module Spectator
     # Yields to run the test code and returns information about the outcome.
     # Returns a tuple with the elapsed time and an error if one occurred (otherwise nil).
     private def capture(&) : Tuple(Time::Span, Exception?)
-      error = nil
-      elapsed = Time.measure do
-        error = catch { yield }
+      Mocks::Scope.push do
+        error = nil
+        elapsed = Time.measure do
+          error = catch { yield }
+        end
+        {elapsed, error}
       end
-      {elapsed, error}
     end
 
     # Yields to run a block of code and captures exceptions.