diff --git a/NEWS b/NEWS
index fca1a2a1478..3f7c5c8e3c7 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,8 @@ PHP                                                                        NEWS
 |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 ?? ??? 2020, PHP 7.4.13
 
+- IMAP:
+  . Fixed bug #64076 (imap_sort() does not return FALSE on failure). (cmb)
 
 29 Oct 2020, PHP 7.4.12
 
diff --git a/ext/imap/php_imap.c b/ext/imap/php_imap.c
index 6a7cfe7037e..fde64aeae18 100644
--- a/ext/imap/php_imap.c
+++ b/ext/imap/php_imap.c
@@ -3199,6 +3199,9 @@ PHP_FUNCTION(imap_sort)
 	} else {
 		spg = mail_newsearchpgm();
 	}
+	if (spg == NIL) {
+		RETURN_FALSE;
+	}
 
 	mypgm = mail_newsortpgm();
 	mypgm->reverse = rev;
diff --git a/ext/imap/tests/bug64076.phpt b/ext/imap/tests/bug64076.phpt
new file mode 100644
index 00000000000..ccafcfe2513
--- /dev/null
+++ b/ext/imap/tests/bug64076.phpt
@@ -0,0 +1,23 @@
+--TEST--
+Bug #64076 (imap_sort() does not return FALSE on failure)
+--SKIPIF--
+<?php
+require_once __DIR__ . '/skipif.inc';
+?>
+--FILE--
+<?php
+require_once __DIR__ . '/imap_include.inc';
+$stream = setup_test_mailbox('', 2);
+imap_errors(); // clear error stack
+var_dump(imap_sort($stream, SORTFROM, 0, 0, 'UNSUPPORTED SEARCH CRITERIUM'));
+var_dump(imap_errors() !== false);
+?>
+--CLEAN--
+<?php
+require_once __DIR__ . '/clean.inc';
+?>
+--EXPECT--
+Create a temporary mailbox and add 2 msgs
+.. mailbox '{127.0.0.1:143/norsh}INBOX.phpttest' created
+bool(false)
+bool(true)