diff --git a/error.go b/error.go
index 3414019..1b61377 100644
--- a/error.go
+++ b/error.go
@@ -2,6 +2,7 @@ package pgsql
 
 import (
 	"errors"
+	"reflect"
 	"regexp"
 
 	"github.com/lib/pq"
@@ -41,14 +42,13 @@ func IsErrorClass(err error, class string) bool {
 // IsUniqueViolation checks is error an unique_violation with given constraint,
 // constraint can be empty to ignore constraint name checks
 func IsUniqueViolation(err error, constraint ...string) bool {
-	var pqErr *pq.Error
-	if errors.As(err, &pqErr) && pqErr.Code == "23505" {
-		if len(constraint) == 0 {
-			return true
-		}
-		return contains(constraint, extractConstraint(pqErr))
+	if !IsErrorCode(err, "23505") { // for drivers that implement sqlState
+		return false
 	}
-	return false
+	if len(constraint) == 0 {
+		return true
+	}
+	return contains(constraint, extractConstraint(err))
 }
 
 // IsInvalidTextRepresentation checks is error an invalid_text_representation
@@ -61,16 +61,15 @@ func IsCharacterNotInRepertoire(err error) bool {
 	return IsErrorCode(err, "22021")
 }
 
-// IsForeignKeyViolation checks is error an foreign_key_violation
+// IsForeignKeyViolation checks is error a foreign_key_violation
 func IsForeignKeyViolation(err error, constraint ...string) bool {
-	var pqErr *pq.Error
-	if errors.As(err, &pqErr) && pqErr.Code == "23503" {
-		if len(constraint) == 0 {
-			return true
-		}
-		return contains(constraint, extractConstraint(pqErr))
+	if !IsErrorCode(err, "23503") { // for drivers that implement sqlState
+		return false
 	}
-	return false
+	if len(constraint) == 0 {
+		return true
+	}
+	return contains(constraint, extractConstraint(err))
 }
 
 // IsQueryCanceled checks is error an query_canceled error
@@ -85,19 +84,39 @@ func IsSerializationFailure(err error) bool {
 	return IsErrorCode(err, "40001")
 }
 
-func extractConstraint(err *pq.Error) string {
-	if err.Constraint != "" {
-		return err.Constraint
-	}
-	if err.Message == "" {
-		return ""
-	}
-	if s := extractCRDBKey(err.Message); s != "" {
-		return s
+func extractConstraint(err error) string {
+	{ // pq
+		var pqErr *pq.Error
+		if errors.As(err, &pqErr) {
+			if pqErr.Constraint != "" {
+				return pqErr.Constraint
+			}
+			if pqErr.Message == "" {
+				return ""
+			}
+			if s := extractCRDBKey(pqErr.Message); s != "" {
+				return s
+			}
+			if s := extractLastQuote(pqErr.Message); s != "" {
+				return s
+			}
+			return ""
+		}
 	}
-	if s := extractLastQuote(err.Message); s != "" {
-		return s
+
+	{ // pgx
+		v := reflect.ValueOf(err)
+		if v.Kind() == reflect.Ptr {
+			v = v.Elem()
+		}
+		if v.Kind() != reflect.Struct {
+			return ""
+		}
+		if f := v.FieldByName("ConstraintName"); f.IsValid() {
+			return f.String()
+		}
 	}
+
 	return ""
 }
 
diff --git a/error_test.go b/error_test.go
index 961b75b..1b1dbe3 100644
--- a/error_test.go
+++ b/error_test.go
@@ -11,6 +11,19 @@ import (
 	"github.com/acoshift/pgsql"
 )
 
+type pgxError struct {
+	Code           string
+	ConstraintName string
+}
+
+func (e *pgxError) Error() string {
+	return "pgxError"
+}
+
+func (e *pgxError) SQLState() string {
+	return e.Code
+}
+
 func TestIsUniqueViolation(t *testing.T) {
 	t.Parallel()
 
@@ -45,6 +58,21 @@ func TestIsUniqueViolation(t *testing.T) {
 		Table:      "users",
 		Constraint: "users_email_key",
 	}))
+
+	assert.True(t, pgsql.IsUniqueViolation(&pgxError{
+		Code:           "23505",
+		ConstraintName: "users_email_key",
+	}))
+
+	assert.True(t, pgsql.IsUniqueViolation(&pgxError{
+		Code:           "23505",
+		ConstraintName: "users_email_key",
+	}, "users_email_key"))
+
+	assert.False(t, pgsql.IsUniqueViolation(&pgxError{
+		Code:           "23505",
+		ConstraintName: "users_email_key",
+	}, "pkey"))
 }
 
 func TestIsForeignKeyViolation(t *testing.T) {