diff --git a/OpenSim/Region/CoreModules/World/Terrain/TerrainModule.cs b/OpenSim/Region/CoreModules/World/Terrain/TerrainModule.cs
index 56ceffd1c9..d0a03cb3bc 100644
--- a/OpenSim/Region/CoreModules/World/Terrain/TerrainModule.cs
+++ b/OpenSim/Region/CoreModules/World/Terrain/TerrainModule.cs
@@ -1171,7 +1171,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain
                     m_channel[x, y] -= (double) args[0];
         }
 
-        private void InterfaceFillTerrain(Object[] args)
+        public void InterfaceFillTerrain(Object[] args)
         {
             int x, y;
 
diff --git a/OpenSim/Region/CoreModules/World/Terrain/Tests/TerrainModuleTests.cs b/OpenSim/Region/CoreModules/World/Terrain/Tests/TerrainModuleTests.cs
new file mode 100644
index 0000000000..0563ad06ce
--- /dev/null
+++ b/OpenSim/Region/CoreModules/World/Terrain/Tests/TerrainModuleTests.cs
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using NUnit.Framework;
+using OpenSim.Framework;
+using OpenSim.Region.CoreModules.World.Terrain;
+using OpenSim.Region.Framework.Scenes;
+using OpenSim.Tests.Common;
+
+namespace OpenSim.Region.CoreModules.Terrain.Tests
+{
+    public class TerrainModuleTests : OpenSimTestCase
+    {
+        [Test]
+        public void TestTerrainFill()
+        {
+            TestHelpers.InMethod();
+//            TestHelpers.EnableLogging();
+
+            //UUID userId = TestHelpers.ParseTail(0x1);
+
+            TerrainModule tm = new TerrainModule();
+            Scene scene = new SceneHelpers().SetupScene();            
+            SceneHelpers.SetupSceneModules(scene, tm);             
+
+            // Fillheight of 30
+            {
+                double fillHeight = 30;
+
+                tm.InterfaceFillTerrain(new object[] { fillHeight });
+
+                double height = scene.Heightmap[128, 128];
+
+                Assert.AreEqual(fillHeight, height);
+            }
+
+            // Max fillheight of 30
+            // According to http://wiki.secondlife.com/wiki/Tips_for_Creating_Heightfields_and_Details_on_Terrain_RAW_Files#Notes_for_Creating_Height_Field_Maps_for_Second_Life
+            {
+                double fillHeight = 508;
+
+                tm.InterfaceFillTerrain(new object[] { fillHeight });
+
+                double height = scene.Heightmap[128, 128];
+
+                Assert.AreEqual(fillHeight, height);
+            }
+        }
+    }
+}
\ No newline at end of file