diff --git a/lib/behat/lib.php b/lib/behat/lib.php
index ff53aab8318..313cd082005 100644
--- a/lib/behat/lib.php
+++ b/lib/behat/lib.php
@@ -461,26 +461,40 @@ function behat_get_run_process() {
             }
         }
     } else if (defined('BEHAT_TEST') || defined('BEHAT_UTIL')) {
-        if ($match = preg_filter('#--run=(.+)#', '$1', $argv)) {
-            $behatrunprocess = reset($match);
-        } else if ($k = array_search('--config', $argv)) {
-            $behatconfig = str_replace("\\", "/", $argv[$k + 1]);
-            // Try get it from config if present.
-            if (!empty($CFG->behat_parallel_run)) {
-                foreach ($CFG->behat_parallel_run as $run => $parallelconfig) {
-                    if (!empty($parallelconfig['behat_dataroot']) &&
-                        $parallelconfig['behat_dataroot'] . '/behat/behat.yml' == $behatconfig) {
+        $behatconfig = '';
 
-                        $behatrunprocess = $run + 1; // We start process from 1.
-                        break;
+        if ($match = preg_filter('#--run=(.+)#', '$1', $argv)) {
+            // Try to guess the run from the existence of the --run arg.
+            $behatrunprocess = reset($match);
+
+        } else {
+            // Try to guess the run from the existence of the --config arg. Note there are 2 alternatives below.
+            if ($k = array_search('--config', $argv)) {
+                // Alternative 1: --config /path/to/config.yml => (next arg, pick it).
+                $behatconfig = str_replace("\\", "/", $argv[$k + 1]);
+
+            } else if ($config = preg_filter('#^(?:--config[ =]*)(.+)$#', '$1', $argv)) {
+                // Alternative 2: --config=/path/to/config.yml => (same arg, just get the path part).
+                $behatconfig = str_replace("\\", "/", reset($config));
+            }
+
+            // Try get it from config if present.
+            if ($behatconfig) {
+                if (!empty($CFG->behat_parallel_run)) {
+                    foreach ($CFG->behat_parallel_run as $run => $parallelconfig) {
+                        if (!empty($parallelconfig['behat_dataroot']) &&
+                                $parallelconfig['behat_dataroot'] . '/behat/behat.yml' == $behatconfig) {
+                            $behatrunprocess = $run + 1; // We start process from 1.
+                            break;
+                        }
                     }
                 }
-            }
-            // Check if default behat datroot increment was done.
-            if (empty($behatrunprocess)) {
-                $behatdataroot = str_replace("\\", "/", $CFG->behat_dataroot . '/' . BEHAT_PARALLEL_SITE_NAME);
-                $behatrunprocess = preg_filter("#^{$behatdataroot}" . "(.+?)[/|\\\]behat[/|\\\]behat\.yml#", '$1',
-                    $behatconfig);
+                // Check if default behat dataroot increment was done.
+                if (empty($behatrunprocess)) {
+                    $behatdataroot = str_replace("\\", "/", $CFG->behat_dataroot . '/' . BEHAT_PARALLEL_SITE_NAME);
+                    $behatrunprocess = preg_filter("#^{$behatdataroot}" . "(.+?)[/|\\\]behat[/|\\\]behat\.yml#", '$1',
+                        $behatconfig);
+                }
             }
         }
     }