diff --git a/LayoutTests/ChangeLog b/LayoutTests/ChangeLog
index e949e2d95b63..3538ab9131f0 100644
--- a/LayoutTests/ChangeLog
+++ b/LayoutTests/ChangeLog
@@ -1,3 +1,12 @@
+2017-10-10  Joanmarie Diggs  <jdiggs@igalia.com>
+
+        AX: [ATK] ARIA form role should be mapped to ATK_ROLE_LANDMARK; not ATK_ROLE_FORM
+        https://bugs.webkit.org/show_bug.cgi?id=178137
+
+        Reviewed by Chris Fleizach.
+
+        * platform/gtk/accessibility/roles-exposed-expected.txt: Updated expectations.
+
 2017-10-10  Joanmarie Diggs  <jdiggs@igalia.com>
 
         AX: [ATK] STATE_CHECKABLE should be removed from radio buttons in radiogroups with aria-readonly="true"
diff --git a/LayoutTests/platform/gtk/accessibility/roles-exposed-expected.txt b/LayoutTests/platform/gtk/accessibility/roles-exposed-expected.txt
index 0f1738d35e49..be93fe7d917c 100644
--- a/LayoutTests/platform/gtk/accessibility/roles-exposed-expected.txt
+++ b/LayoutTests/platform/gtk/accessibility/roles-exposed-expected.txt
@@ -647,7 +647,7 @@ div[role=figure]
       AXRole: AXGroup
       
 div[role=form]
-      AXRole: AXForm
+      AXRole: AXLandmarkForm
       
 div[role=grid]
       AXRole: AXTable
diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index 24cc98b2306a..3be80296835f 100644
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,18 @@
+2017-10-10  Joanmarie Diggs  <jdiggs@igalia.com>
+
+        AX: [ATK] ARIA form role should be mapped to ATK_ROLE_LANDMARK; not ATK_ROLE_FORM
+        https://bugs.webkit.org/show_bug.cgi?id=178137
+
+        Reviewed by Chris Fleizach.
+
+        Expose the ARIA form role as ATK_ROLE_LANDMARK; continue to expose the HTML form
+        element as ATK_ROLE_FORM.
+
+        No new tests needed due to existing coverage. Update expectations for roles-exposed.html.
+
+        * accessibility/atk/WebKitAccessibleWrapperAtk.cpp:
+        (atkRole):
+
 2017-10-10  Joanmarie Diggs  <jdiggs@igalia.com>
 
         AX: [ATK] STATE_CHECKABLE should be removed from radio buttons in radiogroups with aria-readonly="true"
diff --git a/Source/WebCore/accessibility/atk/WebKitAccessibleWrapperAtk.cpp b/Source/WebCore/accessibility/atk/WebKitAccessibleWrapperAtk.cpp
index c536db691132..bdc91c396770 100644
--- a/Source/WebCore/accessibility/atk/WebKitAccessibleWrapperAtk.cpp
+++ b/Source/WebCore/accessibility/atk/WebKitAccessibleWrapperAtk.cpp
@@ -773,6 +773,10 @@ static AtkRole atkRole(AccessibilityObject* coreObject)
     case FooterRole:
         return ATK_ROLE_FOOTER;
     case FormRole:
+#if ATK_CHECK_VERSION(2, 11, 3)
+        if (coreObject->ariaRoleAttribute() != UnknownRole)
+            return ATK_ROLE_LANDMARK;
+#endif
         return ATK_ROLE_FORM;
     case CanvasRole:
         return ATK_ROLE_CANVAS;
diff --git a/Tools/ChangeLog b/Tools/ChangeLog
index 1a974b68caab..1c5c65dfe244 100644
--- a/Tools/ChangeLog
+++ b/Tools/ChangeLog
@@ -1,3 +1,14 @@
+2017-10-10  Joanmarie Diggs  <jdiggs@igalia.com>
+
+        AX: [ATK] ARIA form role should be mapped to ATK_ROLE_LANDMARK; not ATK_ROLE_FORM
+        https://bugs.webkit.org/show_bug.cgi?id=178137
+
+        Reviewed by Chris Fleizach.
+
+        Add handling for ATK_ROLE_LANDMARK resulting from the ARIA form role.
+
+        * WebKitTestRunner/InjectedBundle/atk/AccessibilityUIElementAtk.cpp:
+
 2017-10-03  Joanmarie Diggs  <jdiggs@igalia.com>
 
         AX: [ATK] ARIA drag-and-drop attribute values should be exposed via AtkObject attributes
diff --git a/Tools/WebKitTestRunner/InjectedBundle/atk/AccessibilityUIElementAtk.cpp b/Tools/WebKitTestRunner/InjectedBundle/atk/AccessibilityUIElementAtk.cpp
index 4502b894e954..47b2e6704e33 100644
--- a/Tools/WebKitTestRunner/InjectedBundle/atk/AccessibilityUIElementAtk.cpp
+++ b/Tools/WebKitTestRunner/InjectedBundle/atk/AccessibilityUIElementAtk.cpp
@@ -125,6 +125,7 @@ const String attributesMap[][2] = {
 const char* landmarkStringBanner = "AXLandmarkBanner";
 const char* landmarkStringComplementary = "AXLandmarkComplementary";
 const char* landmarkStringContentinfo = "AXLandmarkContentInfo";
+const char* landmarkStringForm = "AXLandmarkForm";
 const char* landmarkStringMain = "AXLandmarkMain";
 const char* landmarkStringNavigation = "AXLandmarkNavigation";
 const char* landmarkStringRegion = "AXLandmarkRegion";
@@ -394,6 +395,8 @@ const gchar* roleToString(AtkObject* object)
             return landmarkStringRegion;
         if (equalLettersIgnoringASCIICase(xmlRolesValue, "doc-toc"))
             return landmarkStringRegion;
+        if (equalLettersIgnoringASCIICase(xmlRolesValue, "form"))
+            return landmarkStringForm;
         if (equalLettersIgnoringASCIICase(xmlRolesValue, "main"))
             return landmarkStringMain;
         if (equalLettersIgnoringASCIICase(xmlRolesValue, "navigation"))