diff --git a/codegen/projections/rails_json/lib/rails_json/types.rb b/codegen/projections/rails_json/lib/rails_json/types.rb
index c3f783dc7..f78391aef 100644
--- a/codegen/projections/rails_json/lib/rails_json/types.rb
+++ b/codegen/projections/rails_json/lib/rails_json/types.rb
@@ -1990,10 +1990,6 @@ def initialize(name:, value:)
         def to_h
           { unknown: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::Unknown #{__getobj__ || 'nil'}>"
-        end
       end
     end
 
@@ -2489,10 +2485,6 @@ def initialize(name:, value:)
         def to_h
           { unknown: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::Unknown #{__getobj__ || 'nil'}>"
-        end
       end
     end
 
@@ -3390,10 +3382,6 @@ def initialize(name:, value:)
         def to_h
           { unknown: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::Unknown #{__getobj__ || 'nil'}>"
-        end
       end
     end
 
@@ -3424,10 +3412,6 @@ def initialize(name:, value:)
         def to_h
           { unknown: super(__getobj__) }
         end
-
-        def to_s
-          "#<RailsJson::Types::Unknown #{__getobj__ || 'nil'}>"
-        end
       end
     end
 
diff --git a/codegen/projections/white_label/lib/white_label/types.rb b/codegen/projections/white_label/lib/white_label/types.rb
index bea8a9baa..4de411bc8 100644
--- a/codegen/projections/white_label/lib/white_label/types.rb
+++ b/codegen/projections/white_label/lib/white_label/types.rb
@@ -1202,10 +1202,6 @@ def initialize(name:, value:)
         def to_h
           { unknown: super(__getobj__) }
         end
-
-        def to_s
-          "#<WhiteLabel::Types::Unknown #{__getobj__ || 'nil'}>"
-        end
       end
     end
 
diff --git a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/types/UnionGenerator.java b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/types/UnionGenerator.java
index df0bb69a8..8cacdbd5d 100644
--- a/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/types/UnionGenerator.java
+++ b/codegen/smithy-ruby-codegen/src/main/java/software/amazon/smithy/ruby/codegen/generators/types/UnionGenerator.java
@@ -78,10 +78,6 @@ public void render() {
                     .openBlock("def to_h")
                     .write("{ unknown: super(__getobj__) }")
                     .closeBlock("end")
-                    .write("")
-                    .openBlock("def to_s")
-                    .write("\"#<$L::Types::Unknown #{__getobj__ || 'nil'}>\"", settings.getModule())
-                    .closeBlock("end")
                     .closeBlock("end")
                     .closeBlock("end\n");
         });