diff --git a/src/spectator/mocks/exception_stub.cr b/src/spectator/mocks/exception_stub.cr
index af92777..c4ce361 100644
--- a/src/spectator/mocks/exception_stub.cr
+++ b/src/spectator/mocks/exception_stub.cr
@@ -12,7 +12,7 @@ module Spectator
     end
 
     # Returns a new stub with constrained arguments.
-    def with(constraint : AbstractArguments)
+    def with_constraint(constraint : AbstractArguments)
       self.class.new(method, @exception, constraint, location)
     end
 
diff --git a/src/spectator/mocks/multi_value_stub.cr b/src/spectator/mocks/multi_value_stub.cr
index 8e1a403..573a418 100644
--- a/src/spectator/mocks/multi_value_stub.cr
+++ b/src/spectator/mocks/multi_value_stub.cr
@@ -16,7 +16,7 @@ module Spectator
     end
 
     # Returns a new stub with constrained arguments.
-    def with(constraint : AbstractArguments)
+    def with_constraint(constraint : AbstractArguments)
       self.class.new(method, @values, constraint, location)
     end
 
diff --git a/src/spectator/mocks/null_stub.cr b/src/spectator/mocks/null_stub.cr
index 8c2d6d3..c1f3594 100644
--- a/src/spectator/mocks/null_stub.cr
+++ b/src/spectator/mocks/null_stub.cr
@@ -9,7 +9,7 @@ module Spectator
     end
 
     # Returns a new stub with constrained arguments.
-    def with(constraint : AbstractArguments)
+    def with_constraint(constraint : AbstractArguments)
       self.class.new(method, constraint, location)
     end
   end
diff --git a/src/spectator/mocks/proc_stub.cr b/src/spectator/mocks/proc_stub.cr
index d20cc9c..c62e566 100644
--- a/src/spectator/mocks/proc_stub.cr
+++ b/src/spectator/mocks/proc_stub.cr
@@ -11,7 +11,7 @@ module Spectator
     end
 
     # Returns a new stub with constrained arguments.
-    def with(constraint : AbstractArguments)
+    def with_constraint(constraint : AbstractArguments)
       self.class.new(method, @proc, constraint, location)
     end
 
diff --git a/src/spectator/mocks/stub_modifiers.cr b/src/spectator/mocks/stub_modifiers.cr
index bb7662c..9daf2af 100644
--- a/src/spectator/mocks/stub_modifiers.cr
+++ b/src/spectator/mocks/stub_modifiers.cr
@@ -4,12 +4,12 @@ module Spectator
   # Mixin intended for `Stub` to return new, modified stubs.
   module StubModifiers
     # Returns a new stub of the same type with constrained arguments.
-    abstract def with(constraint : AbstractArguments)
+    abstract def with_constraint(constraint : AbstractArguments)
 
     # :ditto:
     def with(*args, **kwargs)
-      constraint = Arguments.new(args, kwargs)
-      self.with(constraint)
+      constraint = Arguments.new(args, kwargs).as(AbstractArguments)
+      self.with_constraint(constraint)
     end
   end
 end
diff --git a/src/spectator/mocks/value_stub.cr b/src/spectator/mocks/value_stub.cr
index 5783a5a..cd7f6d2 100644
--- a/src/spectator/mocks/value_stub.cr
+++ b/src/spectator/mocks/value_stub.cr
@@ -12,7 +12,7 @@ module Spectator
     end
 
     # Returns a new stub with constrained arguments.
-    def with(constraint : AbstractArguments)
+    def with_constraint(constraint : AbstractArguments)
       self.class.new(method, @value, constraint, location)
     end