diff --git a/debian/control b/debian/control
index 064f1ea58c..c2412e11c3 100644
--- a/debian/control
+++ b/debian/control
@@ -41,6 +41,8 @@ Depends: ${misc:Depends}, ${python:Depends}, ${shlibs:Depends}
         ,python-numpy
 # for PNG and JPEG support:
         ,python-imaging
+# scrolling detection:
+        ,python-xxhash
 # ffmpeg based codecs:
         ,ffmpeg-xpra
 # packet encoder:
diff --git a/rpmbuild/xpra.spec b/rpmbuild/xpra.spec
index 1803b5d8f9..0ff51555c6 100644
--- a/rpmbuild/xpra.spec
+++ b/rpmbuild/xpra.spec
@@ -180,6 +180,7 @@ Requires: which
 Requires: %{py2prefix}-netifaces
 Requires: %{py2prefix}-rencode
 Requires: %{py2prefix}-pillow
+Requires: python2-xxhash
 Requires: libfakeXinerama
 Requires: gtk2-immodule-xim
 Requires: %{requires_xorg}
@@ -280,6 +281,7 @@ Requires: python %{py3requires_opengl} %{py3requires_sound} %{py3requires_lzo} %
 Requires: python3-lz4
 Requires: python3-gobject
 Requires: python3-pillow
+Requires: python3-xxhash
 Requires: %{py3requires_crypto}
 #TODO:
 #Requires: dbus-python