diff --git a/pgtype/hstore.go b/pgtype/hstore.go
index f3ae78380..ca0c3f6f7 100644
--- a/pgtype/hstore.go
+++ b/pgtype/hstore.go
@@ -6,7 +6,6 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
-	"strings"
 	"unicode"
 	"unicode/utf8"
 
@@ -137,13 +136,20 @@ func (encodePlanHstoreCodecText) Encode(value any, buf []byte) (newBuf []byte, e
 			buf = append(buf, ',')
 		}
 
-		buf = append(buf, quoteHstoreElementIfNeeded(k)...)
+		// unconditionally quote hstore keys/values like Postgres does
+		// this avoids a Mac OS X Postgres hstore parsing bug:
+		// https://www.postgresql.org/message-id/CA%2BHWA9awUW0%2BRV_gO9r1ABZwGoZxPztcJxPy8vMFSTbTfi4jig%40mail.gmail.com
+		buf = append(buf, '"')
+		buf = append(buf, quoteArrayReplacer.Replace(k)...)
+		buf = append(buf, '"')
 		buf = append(buf, "=>"...)
 
 		if v == nil {
 			buf = append(buf, "NULL"...)
 		} else {
-			buf = append(buf, quoteHstoreElementIfNeeded(*v)...)
+			buf = append(buf, '"')
+			buf = append(buf, quoteArrayReplacer.Replace(*v)...)
+			buf = append(buf, '"')
 		}
 	}
 
@@ -271,19 +277,6 @@ func (c HstoreCodec) DecodeValue(m *Map, oid uint32, format int16, src []byte) (
 	return hstore, nil
 }
 
-func quoteHstoreElementIfNeeded(src string) string {
-	// Double-quote keys and values that include whitespace, commas, =s or >s. To include a double
-	// quote or a backslash in a key or value, escape it with a backslash.
-	// From: https://www.postgresql.org/docs/current/hstore.html
-	// whitespace appears to be defined as the isspace() C function: \t\n\v\f\r\n and space
-	const quoteRequiredChars = `,"\=> ` + "\t\n\v\f\r"
-	if src == "" || (len(src) == 4 && strings.ToLower(src) == "null") || strings.ContainsAny(src, quoteRequiredChars) {
-		return quoteArrayElement(src)
-	}
-
-	return src
-}
-
 const (
 	hsPre = iota
 	hsKey
diff --git a/pgtype/hstore_test.go b/pgtype/hstore_test.go
index aa6881c5c..e2b6bb4ef 100644
--- a/pgtype/hstore_test.go
+++ b/pgtype/hstore_test.go
@@ -129,6 +129,9 @@ func TestHstoreCodec(t *testing.T) {
 		"form\\ffeed",
 		"carriage\rreturn",
 		"curly{}braces",
+		// Postgres on Mac OS X hstore parsing bug:
+		// ą = "\xc4\x85" in UTF-8; isspace(0x85) on Mac OS X returns true instead of false
+		"mac_bugą",
 	}
 	for _, s := range specialStrings {
 		// Special key values
@@ -255,3 +258,33 @@ func TestParseInvalidInputs(t *testing.T) {
 		}
 	}
 }
+
+func BenchmarkHstoreEncode(b *testing.B) {
+	stringPtr := func(s string) *string {
+		return &s
+	}
+	h := pgtype.Hstore{"a x": stringPtr("100"), "b": stringPtr("200"), "c": stringPtr("300"),
+		"d": stringPtr("400"), "e": stringPtr("500")}
+
+	serializeConfigs := []struct {
+		name       string
+		encodePlan pgtype.EncodePlan
+	}{
+		{"text", pgtype.HstoreCodec{}.PlanEncode(nil, 0, pgtype.TextFormatCode, h)},
+		{"binary", pgtype.HstoreCodec{}.PlanEncode(nil, 0, pgtype.BinaryFormatCode, h)},
+	}
+
+	for _, serializeConfig := range serializeConfigs {
+		var buf []byte
+		b.Run(serializeConfig.name, func(b *testing.B) {
+			for i := 0; i < b.N; i++ {
+				var err error
+				buf, err = serializeConfig.encodePlan.Encode(h, buf)
+				if err != nil {
+					b.Fatal(err)
+				}
+				buf = buf[:0]
+			}
+		})
+	}
+}