diff --git a/Source/WebKit/ChangeLog b/Source/WebKit/ChangeLog
index 006b6c8daa2c..583386d05fdf 100644
--- a/Source/WebKit/ChangeLog
+++ b/Source/WebKit/ChangeLog
@@ -1,3 +1,15 @@
+2017-08-15  Carlos Garcia Campos  <cgarcia@igalia.com>
+
+        [GTK][WPE] WebKitAutomationSession should set session client to nullptr on dispose
+        https://bugs.webkit.org/show_bug.cgi?id=175564
+
+        Reviewed by Carlos Alberto Lopez Perez.
+
+        WebAutomationSession expects its client to be nullptr in the destructor.
+
+        * UIProcess/API/glib/WebKitAutomationSession.cpp:
+        (webkitAutomationSessionDispose):
+
 2017-08-15  Carlos Garcia Campos  <cgarcia@igalia.com>
 
         WebDriver: timeout when JavaScript alert is shown in onload handler
diff --git a/Source/WebKit/UIProcess/API/glib/WebKitAutomationSession.cpp b/Source/WebKit/UIProcess/API/glib/WebKitAutomationSession.cpp
index 87033bf8d06e..93ab8d507845 100644
--- a/Source/WebKit/UIProcess/API/glib/WebKitAutomationSession.cpp
+++ b/Source/WebKit/UIProcess/API/glib/WebKitAutomationSession.cpp
@@ -199,6 +199,8 @@ static void webkitAutomationSessionDispose(GObject* object)
 {
     WebKitAutomationSession* session = WEBKIT_AUTOMATION_SESSION(object);
 
+    session->priv->session->setClient(nullptr);
+
     if (session->priv->applicationInfo) {
         webkit_application_info_unref(session->priv->applicationInfo);
         session->priv->applicationInfo = nullptr;