diff --git a/stdlib/sql.go b/stdlib/sql.go
index e3307e96..5e8a2ca4 100644
--- a/stdlib/sql.go
+++ b/stdlib/sql.go
@@ -507,26 +507,29 @@ func (r *Rows) Next(dest []driver.Value) error {
 		r.valueFuncs = make([]rowValueFunc, len(fieldDescriptions))
 
 		for i, fd := range fieldDescriptions {
+			dataTypeOID := fd.DataTypeOID
+			format := fd.Format
+
 			switch fd.DataTypeOID {
 			case pgtype.BoolOID:
 				var d bool
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					return d, err
 				}
 			case pgtype.ByteaOID:
 				var d []byte
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					return d, err
 				}
 			case pgtype.CIDOID:
 				var d pgtype.CID
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					if err != nil {
 						return nil, err
 					}
@@ -534,9 +537,9 @@ func (r *Rows) Next(dest []driver.Value) error {
 				}
 			case pgtype.DateOID:
 				var d pgtype.Date
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					if err != nil {
 						return nil, err
 					}
@@ -544,44 +547,44 @@ func (r *Rows) Next(dest []driver.Value) error {
 				}
 			case pgtype.Float4OID:
 				var d float32
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					return float64(d), err
 				}
 			case pgtype.Float8OID:
 				var d float64
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					return d, err
 				}
 			case pgtype.Int2OID:
 				var d int16
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					return int64(d), err
 				}
 			case pgtype.Int4OID:
 				var d int32
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					return int64(d), err
 				}
 			case pgtype.Int8OID:
 				var d int64
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					return d, err
 				}
 			case pgtype.JSONOID:
 				var d pgtype.JSON
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					if err != nil {
 						return nil, err
 					}
@@ -589,9 +592,9 @@ func (r *Rows) Next(dest []driver.Value) error {
 				}
 			case pgtype.JSONBOID:
 				var d pgtype.JSONB
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					if err != nil {
 						return nil, err
 					}
@@ -599,9 +602,9 @@ func (r *Rows) Next(dest []driver.Value) error {
 				}
 			case pgtype.OIDOID:
 				var d pgtype.OIDValue
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					if err != nil {
 						return nil, err
 					}
@@ -609,9 +612,9 @@ func (r *Rows) Next(dest []driver.Value) error {
 				}
 			case pgtype.TimestampOID:
 				var d pgtype.Timestamp
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					if err != nil {
 						return nil, err
 					}
@@ -619,9 +622,9 @@ func (r *Rows) Next(dest []driver.Value) error {
 				}
 			case pgtype.TimestamptzOID:
 				var d pgtype.Timestamptz
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					if err != nil {
 						return nil, err
 					}
@@ -629,9 +632,9 @@ func (r *Rows) Next(dest []driver.Value) error {
 				}
 			case pgtype.XIDOID:
 				var d pgtype.XID
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					if err != nil {
 						return nil, err
 					}
@@ -639,9 +642,9 @@ func (r *Rows) Next(dest []driver.Value) error {
 				}
 			default:
 				var d string
-				scanPlan := ci.PlanScan(fd.DataTypeOID, fd.Format, &d)
+				scanPlan := ci.PlanScan(dataTypeOID, format, &d)
 				r.valueFuncs[i] = func(src []byte) (driver.Value, error) {
-					err := scanPlan.Scan(ci, fd.DataTypeOID, fd.Format, src, &d)
+					err := scanPlan.Scan(ci, dataTypeOID, format, src, &d)
 					return d, err
 				}
 			}
diff --git a/stdlib/sql_test.go b/stdlib/sql_test.go
index 3f6958f2..87d82943 100644
--- a/stdlib/sql_test.go
+++ b/stdlib/sql_test.go
@@ -261,6 +261,22 @@ func TestConnQuery(t *testing.T) {
 	})
 }
 
+// https://github.com/jackc/pgx/issues/781
+func TestConnQueryDifferentScanPlansIssue781(t *testing.T) {
+	testWithAndWithoutPreferSimpleProtocol(t, func(t *testing.T, db *sql.DB) {
+		var s string
+		var b bool
+
+		rows, err := db.Query("select true, 'foo'")
+		require.NoError(t, err)
+
+		require.True(t, rows.Next())
+		require.NoError(t, rows.Scan(&b, &s))
+		assert.Equal(t, true, b)
+		assert.Equal(t, "foo", s)
+	})
+}
+
 func TestConnQueryNull(t *testing.T) {
 	testWithAndWithoutPreferSimpleProtocol(t, func(t *testing.T, db *sql.DB) {
 		rows, err := db.Query("select $1::int", nil)