diff --git a/Effects/water-inland.eff b/Effects/water-inland.eff
index b5003f2fb..59665f0c2 100644
--- a/Effects/water-inland.eff
+++ b/Effects/water-inland.eff
@@ -410,6 +410,11 @@
 				<type>sampler-2d</type>
 				<value type="int">3</value>
 			</uniform>
+			<uniform>
+				<name>topo_map</name>
+				<type>sampler-2d</type>
+				<value type="int">4</value>
+			</uniform>
 			<uniform>
 				<name>sea_foam</name>
 				<type>sampler-2d</type>