diff --git a/pkg/runtime/scheme.go b/pkg/runtime/scheme.go
index 64cacb6d8b1..1e22560a6d3 100644
--- a/pkg/runtime/scheme.go
+++ b/pkg/runtime/scheme.go
@@ -34,36 +34,12 @@ type Scheme struct {
 	raw *conversion.Scheme
 }
 
-var namedSchemes map[string]*Scheme
-
-// GetScheme returns the scheme with the given name, creating it if necessary.
-// Important: You may not modify the returned *Scheme except from init() functions.
-func GetScheme(schemeName string) *Scheme {
-	if namedSchemes == nil {
-		namedSchemes = map[string]*Scheme{}
-	}
-	if s, ok := namedSchemes[schemeName]; ok {
-		return s
-	}
-	s := NewScheme("", "")
-	namedSchemes[schemeName] = s
-	return s
-}
-
 // fromScope gets the input version, desired output version, and desired Scheme
 // from a conversion.Scope.
 func fromScope(s conversion.Scope) (inVersion, outVersion string, scheme *Scheme) {
 	scheme = DefaultScheme
 	inVersion = s.Meta().SrcVersion
 	outVersion = s.Meta().DestVersion
-	// If a scheme tag was provided, use it. Look at the struct tag corresponding
-	// to version "".
-	if name := s.SrcTag().Get("scheme"); inVersion == "" && name != "" {
-		scheme = GetScheme(name)
-	}
-	if name := s.DestTag().Get("scheme"); outVersion == "" && name != "" {
-		scheme = GetScheme(name)
-	}
 	return inVersion, outVersion, scheme
 }
 
diff --git a/pkg/runtime/scheme_test.go b/pkg/runtime/scheme_test.go
index 34a3fcf83a5..c317c6f7efa 100644
--- a/pkg/runtime/scheme_test.go
+++ b/pkg/runtime/scheme_test.go
@@ -153,28 +153,22 @@ type ExternalExtensionType struct {
 }
 
 type InternalExtensionType struct {
-	JSONBase  `json:",inline" yaml:",inline"`
-	Extension runtime.EmbeddedObject `json:"extension" yaml:"extension" scheme:"testExtension"`
-}
-
-type InternalExtensionTypeNoScheme struct {
 	JSONBase  `json:",inline" yaml:",inline"`
 	Extension runtime.EmbeddedObject `json:"extension" yaml:"extension"`
 }
 
-func (*ExtensionA) IsAnAPIObject()                    {}
-func (*ExtensionB) IsAnAPIObject()                    {}
-func (*ExternalExtensionType) IsAnAPIObject()         {}
-func (*InternalExtensionType) IsAnAPIObject()         {}
-func (*InternalExtensionTypeNoScheme) IsAnAPIObject() {}
+func (*ExtensionA) IsAnAPIObject()            {}
+func (*ExtensionB) IsAnAPIObject()            {}
+func (*ExternalExtensionType) IsAnAPIObject() {}
+func (*InternalExtensionType) IsAnAPIObject() {}
 
-func TestExtensionMappingWithScheme(t *testing.T) {
+func TestExtensionMapping(t *testing.T) {
 	runtime.DefaultScheme.AddKnownTypeWithName("", "ExtensionType", &InternalExtensionType{})
-	runtime.GetScheme("testExtension").AddKnownTypeWithName("", "A", &ExtensionA{})
-	runtime.GetScheme("testExtension").AddKnownTypeWithName("", "B", &ExtensionB{})
+	runtime.DefaultScheme.AddKnownTypeWithName("", "A", &ExtensionA{})
+	runtime.DefaultScheme.AddKnownTypeWithName("", "B", &ExtensionB{})
 	runtime.DefaultScheme.AddKnownTypeWithName("testExternal", "ExtensionType", &ExternalExtensionType{})
-	runtime.GetScheme("testExtension").AddKnownTypeWithName("testExternal", "A", &ExtensionA{})
-	runtime.GetScheme("testExtension").AddKnownTypeWithName("testExternal", "B", &ExtensionB{})
+	runtime.DefaultScheme.AddKnownTypeWithName("testExternal", "A", &ExtensionA{})
+	runtime.DefaultScheme.AddKnownTypeWithName("testExternal", "B", &ExtensionB{})
 
 	table := []struct {
 		obj     runtime.Object
@@ -215,43 +209,3 @@ func TestExtensionMappingWithScheme(t *testing.T) {
 		}
 	}
 }
-
-func TestExtensionMappingWithoutScheme(t *testing.T) {
-	runtime.DefaultScheme.AddKnownTypeWithName("", "ExtensionType", &InternalExtensionTypeNoScheme{})
-	runtime.DefaultScheme.AddKnownTypeWithName("", "ExA", &ExtensionA{})
-	runtime.DefaultScheme.AddKnownTypeWithName("testExternal", "ExtensionType", &ExternalExtensionType{})
-	runtime.DefaultScheme.AddKnownTypeWithName("testExternal", "ExA", &ExtensionA{})
-
-	table := []struct {
-		obj     runtime.Object
-		encoded string
-	}{
-		{
-			&InternalExtensionTypeNoScheme{Extension: runtime.EmbeddedObject{&ExtensionA{TestString: "foo"}}},
-			`{"kind":"ExtensionType","apiVersion":"testExternal","extension":{"kind":"ExA","testString":"foo"}}`,
-		},
-	}
-
-	for _, item := range table {
-		gotEncoded, err := runtime.DefaultScheme.EncodeToVersion(item.obj, "testExternal")
-		if err != nil {
-			t.Errorf("unexpected error '%v' (%#v)", err, item.obj)
-		} else if e, a := item.encoded, string(gotEncoded); e != a {
-			t.Errorf("expected %v, got %v", e, a)
-		}
-
-		gotDecoded, err := runtime.DefaultScheme.Decode([]byte(item.encoded))
-		if err != nil {
-			t.Errorf("unexpected error '%v' (%v)", err, item.encoded)
-		} else if e, a := item.obj, gotDecoded; !reflect.DeepEqual(e, a) {
-			var eEx, aEx runtime.Object
-			if obj, ok := e.(*InternalExtensionTypeNoScheme); ok {
-				eEx = obj.Extension.Object
-			}
-			if obj, ok := a.(*InternalExtensionTypeNoScheme); ok {
-				aEx = obj.Extension.Object
-			}
-			t.Errorf("expected %#v, got %#v (%#v, %#v)", e, a, eEx, aEx)
-		}
-	}
-}
diff --git a/pkg/runtime/types.go b/pkg/runtime/types.go
index c361906d2cb..b7ec6a0e169 100644
--- a/pkg/runtime/types.go
+++ b/pkg/runtime/types.go
@@ -72,8 +72,7 @@ type EmbeddedObject struct {
 // // Internal package:
 // type MyAPIObject struct {
 // 	runtime.JSONBase `yaml:",inline" json:",inline"`
-//	// The "scheme" tag is optional; if absent, runtime.DefaultScheme will be used.
-//	MyPlugin runtime.EmbeddedObject `scheme:"pluginScheme"`
+//	MyPlugin runtime.EmbeddedObject `json:"myPlugin" yaml:"myPlugin"`
 // }
 // type PluginA struct {
 // 	runtime.PluginBase `yaml:",inline" json:",inline"`