diff --git a/NEWS b/NEWS
index 779a2e05523..d2508bf5bde 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,10 @@ PHP                                                                        NEWS
     zend.exception_ignore_args=1 into account). (timwolla)
   . Fix fallback paths in fast_long_{add,sub}_function. (nielsdos)
 
+- LDAP:
+  . Fixed bug GH-17704 (ldap_search fails when $attributes contains a
+    non-packed array with numerical keys). (nielsdos, 7u83)
+
 - MBString:
   . Fixed bug GH-17503 (Undefined float conversion in mb_convert_variables).
     (cmb)
diff --git a/ext/ldap/ldap.c b/ext/ldap/ldap.c
index e66ff070577..db4c5ab2310 100644
--- a/ext/ldap/ldap.c
+++ b/ext/ldap/ldap.c
@@ -248,7 +248,7 @@ static bool php_ldap_is_numerically_indexed_array(zend_array *arr)
 		}
 	} ZEND_HASH_FOREACH_END();
 
-	return false;
+	return true;
 }
 
 /* {{{ Parse controls from and to arrays */
diff --git a/ext/ldap/tests/gh17704.phpt b/ext/ldap/tests/gh17704.phpt
new file mode 100644
index 00000000000..2403a63860e
--- /dev/null
+++ b/ext/ldap/tests/gh17704.phpt
@@ -0,0 +1,24 @@
+--TEST--
+GH-17704 (ldap_search fails when $attributes contains a non-packed array with numerical keys)
+--EXTENSIONS--
+ldap
+--SKIPIF--
+<?php
+require_once('skipifbindfailure.inc');
+?>
+--FILE--
+<?php
+include "connect.inc";
+
+$link = ldap_connect_and_bind($uri, $user, $passwd, $protocol_version);
+
+$attributes = ["uid", "cn"];
+// force a non-packed array
+$attributes["x"] = "x";
+unset($attributes["x"]);
+
+var_dump(ldap_search($link, $base, "(o=*)", $attributes));
+?>
+--EXPECTF--
+object(LDAP\Result)#%d (0) {
+}