diff --git a/gfx/layers/apz/src/APZCTreeManager.cpp b/gfx/layers/apz/src/APZCTreeManager.cpp
index bf861f24058c..ecdee2b77b07 100644
--- a/gfx/layers/apz/src/APZCTreeManager.cpp
+++ b/gfx/layers/apz/src/APZCTreeManager.cpp
@@ -1417,7 +1417,8 @@ APZCTreeManager::ProcessTouchInput(MultiTouchInput& aInput,
     // Check if this event starts a scrollbar touch-drag. The conditions
     // checked are similar to the ones we check for MOUSE_INPUT starting
     // a scrollbar mouse-drag.
-    mInScrollbarTouchDrag = gfxPrefs::APZDragEnabled() && hitScrollbarNode &&
+    mInScrollbarTouchDrag = gfxPrefs::APZDragEnabled() &&
+                            gfxPrefs::APZTouchDragEnabled() && hitScrollbarNode &&
                             hitScrollbarNode->IsScrollThumbNode() &&
                             hitScrollbarNode->GetScrollThumbData().mIsAsyncDraggable;
 
diff --git a/gfx/layers/apz/src/AsyncPanZoomController.cpp b/gfx/layers/apz/src/AsyncPanZoomController.cpp
index 9e730e4c06b4..fb953aef4231 100644
--- a/gfx/layers/apz/src/AsyncPanZoomController.cpp
+++ b/gfx/layers/apz/src/AsyncPanZoomController.cpp
@@ -199,6 +199,19 @@ typedef GenericFlingAnimation FlingAnimation;
  * disable the expiry behavior entirely.
  * Units: milliseconds
  *
+ * \li\b apz.drag.enabled
+ * Setting this pref to true will cause APZ to handle mouse-dragging of
+ * scrollbar thumbs.
+ *
+ * \li\b apz.drag.initial.enabled
+ * Setting this pref to true will cause APZ to try to handle mouse-dragging
+ * of scrollbar thumbs without an initial round-trip to content to start it
+ * if possible. Only has an effect if apz.drag.enabled is also true.
+ *
+ * \li\b apz.drag.touch.enabled
+ * Setting this pref to true will cause APZ to handle touch-dragging of
+ * scrollbar thumbs. Only has an effect if apz.drag.enabled is also true.
+ *
  * \li\b apz.enlarge_displayport_when_clipped
  * Pref that enables enlarging of the displayport along one axis when the
  * generated displayport's size is beyond that of the scrollable rect on the
diff --git a/gfx/thebes/gfxPrefs.h b/gfx/thebes/gfxPrefs.h
index 20a5e83f33c3..f84e05fa113e 100644
--- a/gfx/thebes/gfxPrefs.h
+++ b/gfx/thebes/gfxPrefs.h
@@ -298,6 +298,7 @@ private:
   DECL_GFX_PREF(Live, "apz.displayport_expiry_ms",             APZDisplayPortExpiryTime, uint32_t, 15000);
   DECL_GFX_PREF(Live, "apz.drag.enabled",                      APZDragEnabled, bool, false);
   DECL_GFX_PREF(Live, "apz.drag.initial.enabled",              APZDragInitiationEnabled, bool, false);
+  DECL_GFX_PREF(Live, "apz.drag.touch.enabled",                APZTouchDragEnabled, bool, false);
   DECL_GFX_PREF(Live, "apz.enlarge_displayport_when_clipped",  APZEnlargeDisplayPortWhenClipped, bool, false);
   DECL_GFX_PREF(Live, "apz.fling_accel_base_mult",             APZFlingAccelBaseMultiplier, float, 1.0f);
   DECL_GFX_PREF(Live, "apz.fling_accel_interval_ms",           APZFlingAccelInterval, int32_t, 500);
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index e195f5f437c1..6d8f7e6447c6 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -674,6 +674,7 @@ pref("apz.axis_lock.direct_pan_angle", "1.047197");   // PI / 3 (60 degrees)
 pref("apz.content_response_timeout", 400);
 pref("apz.drag.enabled", true);
 pref("apz.drag.initial.enabled", true);
+pref("apz.drag.touch.enabled", true);
 pref("apz.danger_zone_x", 50);
 pref("apz.danger_zone_y", 100);
 pref("apz.disable_for_scroll_linked_effects", false);