diff --git a/pkg/api/v1/types.go b/pkg/api/v1/types.go
index 23f0865190d..d28e82ce530 100644
--- a/pkg/api/v1/types.go
+++ b/pkg/api/v1/types.go
@@ -953,7 +953,7 @@ type PodTemplateList struct {
 
 // ReplicationControllerSpec is the specification of a replication controller.
 type ReplicationControllerSpec struct {
-	// Replicas is the number of desired replicas.
+	// Replicas is the number of desired replicas. This is a pointer to distinguish between explicit zero and unspecified.
 	Replicas *int `json:"replicas,omitempty" description:"number of replicas desired; defaults to 1"`
 
 	// Selector is a label query over pods that should match the Replicas count.
diff --git a/pkg/api/v1beta3/conversion.go b/pkg/api/v1beta3/conversion.go
index 13ecd4411f2..759c9fc0c10 100644
--- a/pkg/api/v1beta3/conversion.go
+++ b/pkg/api/v1beta3/conversion.go
@@ -41,6 +41,8 @@ func addConversionFuncs() {
 		convert_api_StatusDetails_To_v1beta3_StatusDetails,
 		convert_v1beta3_StatusCause_To_api_StatusCause,
 		convert_api_StatusCause_To_v1beta3_StatusCause,
+		convert_api_ReplicationControllerSpec_To_v1beta3_ReplicationControllerSpec,
+		convert_v1beta3_ReplicationControllerSpec_To_api_ReplicationControllerSpec,
 	)
 	if err != nil {
 		// If one of the conversion functions is malformed, detect it immediately.
@@ -726,3 +728,51 @@ func convert_api_StatusCause_To_v1beta3_StatusCause(in *api.StatusCause, out *St
 	out.Field = in.Field
 	return nil
 }
+
+func convert_api_ReplicationControllerSpec_To_v1beta3_ReplicationControllerSpec(in *api.ReplicationControllerSpec, out *ReplicationControllerSpec, s conversion.Scope) error {
+	if defaulting, found := s.DefaultingInterface(reflect.TypeOf(*in)); found {
+		defaulting.(func(*api.ReplicationControllerSpec))(in)
+	}
+	out.Replicas = &in.Replicas
+	if in.Selector != nil {
+		out.Selector = make(map[string]string)
+		for key, val := range in.Selector {
+			out.Selector[key] = val
+		}
+	} else {
+		out.Selector = nil
+	}
+	if in.Template != nil {
+		out.Template = new(PodTemplateSpec)
+		if err := convert_api_PodTemplateSpec_To_v1beta3_PodTemplateSpec(in.Template, out.Template, s); err != nil {
+			return err
+		}
+	} else {
+		out.Template = nil
+	}
+	return nil
+}
+
+func convert_v1beta3_ReplicationControllerSpec_To_api_ReplicationControllerSpec(in *ReplicationControllerSpec, out *api.ReplicationControllerSpec, s conversion.Scope) error {
+	if defaulting, found := s.DefaultingInterface(reflect.TypeOf(*in)); found {
+		defaulting.(func(*ReplicationControllerSpec))(in)
+	}
+	out.Replicas = *in.Replicas
+	if in.Selector != nil {
+		out.Selector = make(map[string]string)
+		for key, val := range in.Selector {
+			out.Selector[key] = val
+		}
+	} else {
+		out.Selector = nil
+	}
+	if in.Template != nil {
+		out.Template = new(api.PodTemplateSpec)
+		if err := convert_v1beta3_PodTemplateSpec_To_api_PodTemplateSpec(in.Template, out.Template, s); err != nil {
+			return err
+		}
+	} else {
+		out.Template = nil
+	}
+	return nil
+}
diff --git a/pkg/api/v1beta3/conversion_generated.go b/pkg/api/v1beta3/conversion_generated.go
index 73be8ca7618..61627f7c9df 100644
--- a/pkg/api/v1beta3/conversion_generated.go
+++ b/pkg/api/v1beta3/conversion_generated.go
@@ -1536,30 +1536,6 @@ func convert_api_ReplicationControllerList_To_v1beta3_ReplicationControllerList(
 	return nil
 }
 
-func convert_api_ReplicationControllerSpec_To_v1beta3_ReplicationControllerSpec(in *api.ReplicationControllerSpec, out *ReplicationControllerSpec, s conversion.Scope) error {
-	if defaulting, found := s.DefaultingInterface(reflect.TypeOf(*in)); found {
-		defaulting.(func(*api.ReplicationControllerSpec))(in)
-	}
-	out.Replicas = in.Replicas
-	if in.Selector != nil {
-		out.Selector = make(map[string]string)
-		for key, val := range in.Selector {
-			out.Selector[key] = val
-		}
-	} else {
-		out.Selector = nil
-	}
-	if in.Template != nil {
-		out.Template = new(PodTemplateSpec)
-		if err := convert_api_PodTemplateSpec_To_v1beta3_PodTemplateSpec(in.Template, out.Template, s); err != nil {
-			return err
-		}
-	} else {
-		out.Template = nil
-	}
-	return nil
-}
-
 func convert_api_ReplicationControllerStatus_To_v1beta3_ReplicationControllerStatus(in *api.ReplicationControllerStatus, out *ReplicationControllerStatus, s conversion.Scope) error {
 	if defaulting, found := s.DefaultingInterface(reflect.TypeOf(*in)); found {
 		defaulting.(func(*api.ReplicationControllerStatus))(in)
@@ -3601,30 +3577,6 @@ func convert_v1beta3_ReplicationControllerList_To_api_ReplicationControllerList(
 	return nil
 }
 
-func convert_v1beta3_ReplicationControllerSpec_To_api_ReplicationControllerSpec(in *ReplicationControllerSpec, out *api.ReplicationControllerSpec, s conversion.Scope) error {
-	if defaulting, found := s.DefaultingInterface(reflect.TypeOf(*in)); found {
-		defaulting.(func(*ReplicationControllerSpec))(in)
-	}
-	out.Replicas = in.Replicas
-	if in.Selector != nil {
-		out.Selector = make(map[string]string)
-		for key, val := range in.Selector {
-			out.Selector[key] = val
-		}
-	} else {
-		out.Selector = nil
-	}
-	if in.Template != nil {
-		out.Template = new(api.PodTemplateSpec)
-		if err := convert_v1beta3_PodTemplateSpec_To_api_PodTemplateSpec(in.Template, out.Template, s); err != nil {
-			return err
-		}
-	} else {
-		out.Template = nil
-	}
-	return nil
-}
-
 func convert_v1beta3_ReplicationControllerStatus_To_api_ReplicationControllerStatus(in *ReplicationControllerStatus, out *api.ReplicationControllerStatus, s conversion.Scope) error {
 	if defaulting, found := s.DefaultingInterface(reflect.TypeOf(*in)); found {
 		defaulting.(func(*ReplicationControllerStatus))(in)
@@ -4238,7 +4190,6 @@ func init() {
 		convert_api_RBDVolumeSource_To_v1beta3_RBDVolumeSource,
 		convert_api_RangeAllocation_To_v1beta3_RangeAllocation,
 		convert_api_ReplicationControllerList_To_v1beta3_ReplicationControllerList,
-		convert_api_ReplicationControllerSpec_To_v1beta3_ReplicationControllerSpec,
 		convert_api_ReplicationControllerStatus_To_v1beta3_ReplicationControllerStatus,
 		convert_api_ReplicationController_To_v1beta3_ReplicationController,
 		convert_api_ResourceQuotaList_To_v1beta3_ResourceQuotaList,
@@ -4345,7 +4296,6 @@ func init() {
 		convert_v1beta3_RBDVolumeSource_To_api_RBDVolumeSource,
 		convert_v1beta3_RangeAllocation_To_api_RangeAllocation,
 		convert_v1beta3_ReplicationControllerList_To_api_ReplicationControllerList,
-		convert_v1beta3_ReplicationControllerSpec_To_api_ReplicationControllerSpec,
 		convert_v1beta3_ReplicationControllerStatus_To_api_ReplicationControllerStatus,
 		convert_v1beta3_ReplicationController_To_api_ReplicationController,
 		convert_v1beta3_ResourceQuotaList_To_api_ResourceQuotaList,
diff --git a/pkg/api/v1beta3/deep_copy_generated.go b/pkg/api/v1beta3/deep_copy_generated.go
index ef17355939f..67f493f6b41 100644
--- a/pkg/api/v1beta3/deep_copy_generated.go
+++ b/pkg/api/v1beta3/deep_copy_generated.go
@@ -1513,7 +1513,12 @@ func deepCopy_v1beta3_ReplicationControllerList(in ReplicationControllerList, ou
 }
 
 func deepCopy_v1beta3_ReplicationControllerSpec(in ReplicationControllerSpec, out *ReplicationControllerSpec, c *conversion.Cloner) error {
-	out.Replicas = in.Replicas
+	if in.Replicas != nil {
+		out.Replicas = new(int)
+		*out.Replicas = *in.Replicas
+	} else {
+		out.Replicas = nil
+	}
 	if in.Selector != nil {
 		out.Selector = make(map[string]string)
 		for key, val := range in.Selector {
diff --git a/pkg/api/v1beta3/defaults.go b/pkg/api/v1beta3/defaults.go
index 5e8793d3318..c7d78bef3e5 100644
--- a/pkg/api/v1beta3/defaults.go
+++ b/pkg/api/v1beta3/defaults.go
@@ -40,6 +40,10 @@ func addDefaultingFuncs() {
 					obj.Labels = labels
 				}
 			}
+			if obj.Spec.Replicas == nil {
+				obj.Spec.Replicas = new(int)
+				*obj.Spec.Replicas = 0
+			}
 		},
 		func(obj *Volume) {
 			if util.AllPtrFieldsNil(&obj.VolumeSource) {
diff --git a/pkg/api/v1beta3/types.go b/pkg/api/v1beta3/types.go
index efe404203c3..fcb367a6b8a 100644
--- a/pkg/api/v1beta3/types.go
+++ b/pkg/api/v1beta3/types.go
@@ -957,8 +957,8 @@ type PodTemplateList struct {
 
 // ReplicationControllerSpec is the specification of a replication controller.
 type ReplicationControllerSpec struct {
-	// Replicas is the number of desired replicas.
-	Replicas int `json:"replicas,omitempty" description:"number of replicas desired"`
+	// Replicas is the number of desired replicas. This is a pointer to distinguish between explicit zero and unspecified.
+	Replicas *int `json:"replicas,omitempty" description:"number of replicas desired"`
 
 	// Selector is a label query over pods that should match the Replicas count.
 	// If Selector is empty, it is defaulted to the labels present on the Pod template.