diff --git a/src/spectator/mocks/generic_method_call.cr b/src/spectator/mocks/generic_method_call.cr
index 628e40f..64f8999 100644
--- a/src/spectator/mocks/generic_method_call.cr
+++ b/src/spectator/mocks/generic_method_call.cr
@@ -8,5 +8,12 @@ module Spectator::Mocks
     def initialize(name : Symbol, @args : GenericArguments(T, NT))
       super(name)
     end
+
+    def to_s(io)
+      super
+      io << '('
+      io << @args
+      io << ')'
+    end
   end
 end
diff --git a/src/spectator/mocks/method_call.cr b/src/spectator/mocks/method_call.cr
index 7c85862..00c6d0c 100644
--- a/src/spectator/mocks/method_call.cr
+++ b/src/spectator/mocks/method_call.cr
@@ -4,5 +4,10 @@ module Spectator::Mocks
 
     def initialize(@name : Symbol)
     end
+
+    def to_s(io)
+      io << '#'
+      io << @name
+    end
   end
 end