diff --git a/pgtype/aclitem.go b/pgtype/aclitem.go
index 36cf3bbf..b8a1549e 100644
--- a/pgtype/aclitem.go
+++ b/pgtype/aclitem.go
@@ -25,8 +25,6 @@ type Aclitem struct {
 
 func (dst *Aclitem) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Aclitem:
-		*dst = value
 	case string:
 		*dst = Aclitem{String: value, Status: Present}
 	case *string:
diff --git a/pgtype/aclitem_array.go b/pgtype/aclitem_array.go
index 13952e5c..5e3647b7 100644
--- a/pgtype/aclitem_array.go
+++ b/pgtype/aclitem_array.go
@@ -16,8 +16,6 @@ type AclitemArray struct {
 
 func (dst *AclitemArray) Set(src interface{}) error {
 	switch value := src.(type) {
-	case AclitemArray:
-		*dst = value
 
 	case []string:
 		if value == nil {
diff --git a/pgtype/aclitem_test.go b/pgtype/aclitem_test.go
index 47e6fa84..1738025a 100644
--- a/pgtype/aclitem_test.go
+++ b/pgtype/aclitem_test.go
@@ -20,7 +20,6 @@ func TestAclitemSet(t *testing.T) {
 		source interface{}
 		result pgtype.Aclitem
 	}{
-		{source: pgtype.Aclitem{String: "postgres=arwdDxt/postgres", Status: pgtype.Present}, result: pgtype.Aclitem{String: "postgres=arwdDxt/postgres", Status: pgtype.Present}},
 		{source: "postgres=arwdDxt/postgres", result: pgtype.Aclitem{String: "postgres=arwdDxt/postgres", Status: pgtype.Present}},
 		{source: (*string)(nil), result: pgtype.Aclitem{Status: pgtype.Null}},
 	}
diff --git a/pgtype/bool.go b/pgtype/bool.go
index 04a261c2..a8e9b8e1 100644
--- a/pgtype/bool.go
+++ b/pgtype/bool.go
@@ -14,8 +14,6 @@ type Bool struct {
 
 func (dst *Bool) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Bool:
-		*dst = value
 	case bool:
 		*dst = Bool{Bool: value, Status: Present}
 	case string:
diff --git a/pgtype/bool_array.go b/pgtype/bool_array.go
index fdcbf7a0..4c5fc563 100644
--- a/pgtype/bool_array.go
+++ b/pgtype/bool_array.go
@@ -17,8 +17,6 @@ type BoolArray struct {
 
 func (dst *BoolArray) Set(src interface{}) error {
 	switch value := src.(type) {
-	case BoolArray:
-		*dst = value
 
 	case []bool:
 		if value == nil {
diff --git a/pgtype/bool_test.go b/pgtype/bool_test.go
index 773bd99b..412e2fd0 100644
--- a/pgtype/bool_test.go
+++ b/pgtype/bool_test.go
@@ -20,7 +20,6 @@ func TestBoolSet(t *testing.T) {
 		source interface{}
 		result pgtype.Bool
 	}{
-		{source: pgtype.Bool{Bool: false, Status: pgtype.Null}, result: pgtype.Bool{Bool: false, Status: pgtype.Null}},
 		{source: true, result: pgtype.Bool{Bool: true, Status: pgtype.Present}},
 		{source: false, result: pgtype.Bool{Bool: false, Status: pgtype.Present}},
 		{source: "true", result: pgtype.Bool{Bool: true, Status: pgtype.Present}},
diff --git a/pgtype/bytea.go b/pgtype/bytea.go
index a8ee55ae..5df05360 100644
--- a/pgtype/bytea.go
+++ b/pgtype/bytea.go
@@ -14,8 +14,6 @@ type Bytea struct {
 
 func (dst *Bytea) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Bytea:
-		*dst = value
 	case []byte:
 		if value != nil {
 			*dst = Bytea{Bytes: value, Status: Present}
diff --git a/pgtype/bytea_array.go b/pgtype/bytea_array.go
index 5362944a..c6f676a4 100644
--- a/pgtype/bytea_array.go
+++ b/pgtype/bytea_array.go
@@ -17,8 +17,6 @@ type ByteaArray struct {
 
 func (dst *ByteaArray) Set(src interface{}) error {
 	switch value := src.(type) {
-	case ByteaArray:
-		*dst = value
 
 	case [][]byte:
 		if value == nil {
diff --git a/pgtype/bytea_test.go b/pgtype/bytea_test.go
index 4655a1c1..e21296c6 100644
--- a/pgtype/bytea_test.go
+++ b/pgtype/bytea_test.go
@@ -20,7 +20,6 @@ func TestByteaSet(t *testing.T) {
 		source interface{}
 		result pgtype.Bytea
 	}{
-		{source: pgtype.Bytea{Bytes: []byte{1, 2, 3}, Status: pgtype.Null}, result: pgtype.Bytea{Bytes: []byte{1, 2, 3}, Status: pgtype.Null}},
 		{source: []byte{1, 2, 3}, result: pgtype.Bytea{Bytes: []byte{1, 2, 3}, Status: pgtype.Present}},
 		{source: []byte{}, result: pgtype.Bytea{Bytes: []byte{}, Status: pgtype.Present}},
 		{source: []byte(nil), result: pgtype.Bytea{Status: pgtype.Null}},
diff --git a/pgtype/date.go b/pgtype/date.go
index a3b8d99f..d0481637 100644
--- a/pgtype/date.go
+++ b/pgtype/date.go
@@ -23,8 +23,6 @@ const (
 
 func (dst *Date) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Date:
-		*dst = value
 	case time.Time:
 		*dst = Date{Time: value, Status: Present}
 	default:
diff --git a/pgtype/date_array.go b/pgtype/date_array.go
index ce28e236..7f602d83 100644
--- a/pgtype/date_array.go
+++ b/pgtype/date_array.go
@@ -18,8 +18,6 @@ type DateArray struct {
 
 func (dst *DateArray) Set(src interface{}) error {
 	switch value := src.(type) {
-	case DateArray:
-		*dst = value
 
 	case []time.Time:
 		if value == nil {
diff --git a/pgtype/date_test.go b/pgtype/date_test.go
index eff3a521..cfc3dd70 100644
--- a/pgtype/date_test.go
+++ b/pgtype/date_test.go
@@ -29,7 +29,6 @@ func TestDateSet(t *testing.T) {
 		source interface{}
 		result pgtype.Date
 	}{
-		{source: pgtype.Date{Time: time.Date(1900, 1, 1, 0, 0, 0, 0, time.UTC), Status: pgtype.Present}, result: pgtype.Date{Time: time.Date(1900, 1, 1, 0, 0, 0, 0, time.UTC), Status: pgtype.Present}},
 		{source: time.Date(1900, 1, 1, 0, 0, 0, 0, time.UTC), result: pgtype.Date{Time: time.Date(1900, 1, 1, 0, 0, 0, 0, time.UTC), Status: pgtype.Present}},
 		{source: time.Date(1970, 1, 1, 0, 0, 0, 0, time.UTC), result: pgtype.Date{Time: time.Date(1970, 1, 1, 0, 0, 0, 0, time.UTC), Status: pgtype.Present}},
 		{source: time.Date(1999, 12, 31, 0, 0, 0, 0, time.UTC), result: pgtype.Date{Time: time.Date(1999, 12, 31, 0, 0, 0, 0, time.UTC), Status: pgtype.Present}},
diff --git a/pgtype/float4.go b/pgtype/float4.go
index a38d24db..053af44b 100644
--- a/pgtype/float4.go
+++ b/pgtype/float4.go
@@ -17,8 +17,6 @@ type Float4 struct {
 
 func (dst *Float4) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Float4:
-		*dst = value
 	case float32:
 		*dst = Float4{Float: value, Status: Present}
 	case float64:
diff --git a/pgtype/float4_array.go b/pgtype/float4_array.go
index 410a8b37..0e815e0b 100644
--- a/pgtype/float4_array.go
+++ b/pgtype/float4_array.go
@@ -17,8 +17,6 @@ type Float4Array struct {
 
 func (dst *Float4Array) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Float4Array:
-		*dst = value
 
 	case []float32:
 		if value == nil {
diff --git a/pgtype/float8.go b/pgtype/float8.go
index 9129e8ba..635b7a09 100644
--- a/pgtype/float8.go
+++ b/pgtype/float8.go
@@ -17,8 +17,6 @@ type Float8 struct {
 
 func (dst *Float8) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Float8:
-		*dst = value
 	case float32:
 		*dst = Float8{Float: float64(value), Status: Present}
 	case float64:
diff --git a/pgtype/float8_array.go b/pgtype/float8_array.go
index b2f70f51..811c5a1f 100644
--- a/pgtype/float8_array.go
+++ b/pgtype/float8_array.go
@@ -17,8 +17,6 @@ type Float8Array struct {
 
 func (dst *Float8Array) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Float8Array:
-		*dst = value
 
 	case []float64:
 		if value == nil {
diff --git a/pgtype/inet.go b/pgtype/inet.go
index 00bfb30c..87d675f9 100644
--- a/pgtype/inet.go
+++ b/pgtype/inet.go
@@ -25,8 +25,6 @@ type Inet struct {
 
 func (dst *Inet) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Inet:
-		*dst = value
 	case net.IPNet:
 		*dst = Inet{IPNet: &value, Status: Present}
 	case *net.IPNet:
diff --git a/pgtype/inet_array.go b/pgtype/inet_array.go
index 4d865b4f..1d1cf3fd 100644
--- a/pgtype/inet_array.go
+++ b/pgtype/inet_array.go
@@ -18,8 +18,6 @@ type InetArray struct {
 
 func (dst *InetArray) Set(src interface{}) error {
 	switch value := src.(type) {
-	case InetArray:
-		*dst = value
 
 	case []*net.IPNet:
 		if value == nil {
diff --git a/pgtype/inet_test.go b/pgtype/inet_test.go
index 90b0723f..16035fca 100644
--- a/pgtype/inet_test.go
+++ b/pgtype/inet_test.go
@@ -31,7 +31,6 @@ func TestInetSet(t *testing.T) {
 		source interface{}
 		result pgtype.Inet
 	}{
-		{source: pgtype.Inet{IPNet: mustParseCidr(t, "127.0.0.1/32"), Status: pgtype.Null}, result: pgtype.Inet{IPNet: mustParseCidr(t, "127.0.0.1/32"), Status: pgtype.Null}},
 		{source: mustParseCidr(t, "127.0.0.1/32"), result: pgtype.Inet{IPNet: mustParseCidr(t, "127.0.0.1/32"), Status: pgtype.Present}},
 		{source: mustParseCidr(t, "127.0.0.1/32").IP, result: pgtype.Inet{IPNet: mustParseCidr(t, "127.0.0.1/32"), Status: pgtype.Present}},
 		{source: "127.0.0.1/32", result: pgtype.Inet{IPNet: mustParseCidr(t, "127.0.0.1/32"), Status: pgtype.Present}},
diff --git a/pgtype/int2.go b/pgtype/int2.go
index 525427c5..62e1bc69 100644
--- a/pgtype/int2.go
+++ b/pgtype/int2.go
@@ -17,8 +17,6 @@ type Int2 struct {
 
 func (dst *Int2) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Int2:
-		*dst = value
 	case int8:
 		*dst = Int2{Int: int16(value), Status: Present}
 	case uint8:
diff --git a/pgtype/int2_array.go b/pgtype/int2_array.go
index 28792fa5..3d06c018 100644
--- a/pgtype/int2_array.go
+++ b/pgtype/int2_array.go
@@ -17,8 +17,6 @@ type Int2Array struct {
 
 func (dst *Int2Array) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Int2Array:
-		*dst = value
 
 	case []int16:
 		if value == nil {
diff --git a/pgtype/int4.go b/pgtype/int4.go
index b3203a28..8eaf5094 100644
--- a/pgtype/int4.go
+++ b/pgtype/int4.go
@@ -17,8 +17,6 @@ type Int4 struct {
 
 func (dst *Int4) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Int4:
-		*dst = value
 	case int8:
 		*dst = Int4{Int: int32(value), Status: Present}
 	case uint8:
diff --git a/pgtype/int4_array.go b/pgtype/int4_array.go
index 61cedb2e..5cd91c04 100644
--- a/pgtype/int4_array.go
+++ b/pgtype/int4_array.go
@@ -17,8 +17,6 @@ type Int4Array struct {
 
 func (dst *Int4Array) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Int4Array:
-		*dst = value
 
 	case []int32:
 		if value == nil {
diff --git a/pgtype/int8.go b/pgtype/int8.go
index 15ad6715..2416500d 100644
--- a/pgtype/int8.go
+++ b/pgtype/int8.go
@@ -17,8 +17,6 @@ type Int8 struct {
 
 func (dst *Int8) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Int8:
-		*dst = value
 	case int8:
 		*dst = Int8{Int: int64(value), Status: Present}
 	case uint8:
diff --git a/pgtype/int8_array.go b/pgtype/int8_array.go
index 9f4373e8..5efc0f45 100644
--- a/pgtype/int8_array.go
+++ b/pgtype/int8_array.go
@@ -17,8 +17,6 @@ type Int8Array struct {
 
 func (dst *Int8Array) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Int8Array:
-		*dst = value
 
 	case []int64:
 		if value == nil {
diff --git a/pgtype/qchar.go b/pgtype/qchar.go
index b6392cf9..d46e716d 100644
--- a/pgtype/qchar.go
+++ b/pgtype/qchar.go
@@ -25,8 +25,6 @@ type QChar struct {
 
 func (dst *QChar) Set(src interface{}) error {
 	switch value := src.(type) {
-	case QChar:
-		*dst = value
 	case int8:
 		*dst = QChar{Int: value, Status: Present}
 	case uint8:
diff --git a/pgtype/text.go b/pgtype/text.go
index 50db2349..3dd082c9 100644
--- a/pgtype/text.go
+++ b/pgtype/text.go
@@ -13,8 +13,6 @@ type Text struct {
 
 func (dst *Text) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Text:
-		*dst = value
 	case string:
 		*dst = Text{String: value, Status: Present}
 	case *string:
diff --git a/pgtype/text_array.go b/pgtype/text_array.go
index 3a5a64ce..1e6677a9 100644
--- a/pgtype/text_array.go
+++ b/pgtype/text_array.go
@@ -17,8 +17,6 @@ type TextArray struct {
 
 func (dst *TextArray) Set(src interface{}) error {
 	switch value := src.(type) {
-	case TextArray:
-		*dst = value
 
 	case []string:
 		if value == nil {
diff --git a/pgtype/text_test.go b/pgtype/text_test.go
index f5e20055..39348bcc 100644
--- a/pgtype/text_test.go
+++ b/pgtype/text_test.go
@@ -22,7 +22,6 @@ func TestTextSet(t *testing.T) {
 		source interface{}
 		result pgtype.Text
 	}{
-		{source: pgtype.Text{String: "foo", Status: pgtype.Present}, result: pgtype.Text{String: "foo", Status: pgtype.Present}},
 		{source: "foo", result: pgtype.Text{String: "foo", Status: pgtype.Present}},
 		{source: _string("bar"), result: pgtype.Text{String: "bar", Status: pgtype.Present}},
 		{source: (*string)(nil), result: pgtype.Text{Status: pgtype.Null}},
diff --git a/pgtype/timestamp.go b/pgtype/timestamp.go
index a84f3881..3bb8f080 100644
--- a/pgtype/timestamp.go
+++ b/pgtype/timestamp.go
@@ -27,8 +27,6 @@ type Timestamp struct {
 // time.Time in a non-UTC time zone, the time zone is discarded.
 func (dst *Timestamp) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Timestamp:
-		*dst = value
 	case time.Time:
 		*dst = Timestamp{Time: time.Date(value.Year(), value.Month(), value.Day(), value.Hour(), value.Minute(), value.Second(), value.Nanosecond(), time.UTC), Status: Present}
 	default:
diff --git a/pgtype/timestamp_array.go b/pgtype/timestamp_array.go
index ec0facb2..c955dc42 100644
--- a/pgtype/timestamp_array.go
+++ b/pgtype/timestamp_array.go
@@ -18,8 +18,6 @@ type TimestampArray struct {
 
 func (dst *TimestampArray) Set(src interface{}) error {
 	switch value := src.(type) {
-	case TimestampArray:
-		*dst = value
 
 	case []time.Time:
 		if value == nil {
diff --git a/pgtype/timestamp_test.go b/pgtype/timestamp_test.go
index 7297ed1f..58828806 100644
--- a/pgtype/timestamp_test.go
+++ b/pgtype/timestamp_test.go
@@ -38,7 +38,6 @@ func TestTimestampSet(t *testing.T) {
 		source interface{}
 		result pgtype.Timestamp
 	}{
-		{source: pgtype.Timestamp{Time: time.Date(1900, 1, 1, 0, 0, 0, 0, time.UTC), Status: pgtype.Present}, result: pgtype.Timestamp{Time: time.Date(1900, 1, 1, 0, 0, 0, 0, time.UTC), Status: pgtype.Present}},
 		{source: time.Date(1900, 1, 1, 0, 0, 0, 0, time.UTC), result: pgtype.Timestamp{Time: time.Date(1900, 1, 1, 0, 0, 0, 0, time.UTC), Status: pgtype.Present}},
 		{source: time.Date(1970, 1, 1, 0, 0, 0, 0, time.UTC), result: pgtype.Timestamp{Time: time.Date(1970, 1, 1, 0, 0, 0, 0, time.UTC), Status: pgtype.Present}},
 		{source: time.Date(1999, 12, 31, 12, 59, 59, 0, time.UTC), result: pgtype.Timestamp{Time: time.Date(1999, 12, 31, 12, 59, 59, 0, time.UTC), Status: pgtype.Present}},
diff --git a/pgtype/timestamptz.go b/pgtype/timestamptz.go
index a6922d5b..5b9f5038 100644
--- a/pgtype/timestamptz.go
+++ b/pgtype/timestamptz.go
@@ -28,8 +28,6 @@ type Timestamptz struct {
 
 func (dst *Timestamptz) Set(src interface{}) error {
 	switch value := src.(type) {
-	case Timestamptz:
-		*dst = value
 	case time.Time:
 		*dst = Timestamptz{Time: value, Status: Present}
 	default:
diff --git a/pgtype/timestamptz_array.go b/pgtype/timestamptz_array.go
index 775ec970..cd63e02e 100644
--- a/pgtype/timestamptz_array.go
+++ b/pgtype/timestamptz_array.go
@@ -18,8 +18,6 @@ type TimestamptzArray struct {
 
 func (dst *TimestamptzArray) Set(src interface{}) error {
 	switch value := src.(type) {
-	case TimestamptzArray:
-		*dst = value
 
 	case []time.Time:
 		if value == nil {
diff --git a/pgtype/timestamptz_test.go b/pgtype/timestamptz_test.go
index 242cd05f..6ddfc1bc 100644
--- a/pgtype/timestamptz_test.go
+++ b/pgtype/timestamptz_test.go
@@ -38,7 +38,6 @@ func TestTimestamptzSet(t *testing.T) {
 		source interface{}
 		result pgtype.Timestamptz
 	}{
-		{source: pgtype.Timestamptz{Time: time.Date(1900, 1, 1, 0, 0, 0, 0, time.Local), Status: pgtype.Present}, result: pgtype.Timestamptz{Time: time.Date(1900, 1, 1, 0, 0, 0, 0, time.Local), Status: pgtype.Present}},
 		{source: time.Date(1900, 1, 1, 0, 0, 0, 0, time.Local), result: pgtype.Timestamptz{Time: time.Date(1900, 1, 1, 0, 0, 0, 0, time.Local), Status: pgtype.Present}},
 		{source: time.Date(1970, 1, 1, 0, 0, 0, 0, time.Local), result: pgtype.Timestamptz{Time: time.Date(1970, 1, 1, 0, 0, 0, 0, time.Local), Status: pgtype.Present}},
 		{source: time.Date(1999, 12, 31, 12, 59, 59, 0, time.Local), result: pgtype.Timestamptz{Time: time.Date(1999, 12, 31, 12, 59, 59, 0, time.Local), Status: pgtype.Present}},
diff --git a/pgtype/typed_array.go.erb b/pgtype/typed_array.go.erb
index c62e2896..a56097c0 100644
--- a/pgtype/typed_array.go.erb
+++ b/pgtype/typed_array.go.erb
@@ -16,8 +16,6 @@ type <%= pgtype_array_type %> struct {
 
 func (dst *<%= pgtype_array_type %>) Set(src interface{}) error {
 	switch value := src.(type) {
-	case <%= pgtype_array_type %>:
-		*dst = value
 	<% go_array_types.split(",").each do |t| %>
 	case <%= t %>:
 		if value == nil {