diff --git a/ext/pgsql/pgsql.c b/ext/pgsql/pgsql.c
index 80aacd5443eaa..99f2e3cf563fe 100644
--- a/ext/pgsql/pgsql.c
+++ b/ext/pgsql/pgsql.c
@@ -705,10 +705,12 @@ static void php_pgsql_do_connect(INTERNAL_FUNCTION_PARAMETERS, int persistent)
 			/* create the link */
 			pgsql = PQconnectdb(connstring);
 			if (pgsql == NULL || PQstatus(pgsql) == CONNECTION_BAD) {
-				PHP_PQ_ERROR("Unable to connect to PostgreSQL server: %s", pgsql)
+				zend_string *msgbuf = _php_pgsql_trim_message(PQerrorMessage(pgsql));
 				if (pgsql) {
 					PQfinish(pgsql);
 				}
+				php_error_docref(NULL, E_WARNING, "Unable to connect to PostgreSQL server: %s", ZSTR_VAL(msgbuf));
+				zend_string_release(msgbuf);
 				goto err;
 			}
 
@@ -789,19 +791,23 @@ static void php_pgsql_do_connect(INTERNAL_FUNCTION_PARAMETERS, int persistent)
 		if (connect_type & PGSQL_CONNECT_ASYNC) {
 			pgsql = PQconnectStart(connstring);
 			if (pgsql==NULL || PQstatus(pgsql)==CONNECTION_BAD) {
-				PHP_PQ_ERROR("Unable to connect to PostgreSQL server: %s", pgsql);
+				zend_string *msgbuf = _php_pgsql_trim_message(PQerrorMessage(pgsql));
 				if (pgsql) {
 					PQfinish(pgsql);
 				}
+				php_error_docref(NULL, E_WARNING, "Unable to connect to PostgreSQL server: %s", ZSTR_VAL(msgbuf));
+				zend_string_release(msgbuf);
 				goto err;
 			}
 		} else {
 			pgsql = PQconnectdb(connstring);
 			if (pgsql==NULL || PQstatus(pgsql)==CONNECTION_BAD) {
-				PHP_PQ_ERROR("Unable to connect to PostgreSQL server: %s", pgsql);
+				zend_string *msgbuf = _php_pgsql_trim_message(PQerrorMessage(pgsql));
 				if (pgsql) {
 					PQfinish(pgsql);
 				}
+				php_error_docref(NULL, E_WARNING, "Unable to connect to PostgreSQL server: %s", ZSTR_VAL(msgbuf));
+				zend_string_release(msgbuf);
 				goto err;
 			}
 		}
diff --git a/ext/pgsql/tests/gh21162.phpt b/ext/pgsql/tests/gh21162.phpt
new file mode 100644
index 0000000000000..9f40ac1136d3c
--- /dev/null
+++ b/ext/pgsql/tests/gh21162.phpt
@@ -0,0 +1,18 @@
+--TEST--
+GH-21162 (pg_connect() on error memory leak)
+--EXTENSIONS--
+pgsql
+--FILE--
+<?php
+
+set_error_handler(function (int $errno, string $errstr) {
+    echo "Warning caught\n";
+});
+
+pg_connect('');
+
+echo "Done\n";
+?>
+--EXPECT--
+Warning caught
+Done