diff --git a/engine/src/test/jme3test/terrain/TerrainFractalGridTest.java b/engine/src/test/jme3test/terrain/TerrainFractalGridTest.java
index b167dc3a1..9cbafd3ef 100644
--- a/engine/src/test/jme3test/terrain/TerrainFractalGridTest.java
+++ b/engine/src/test/jme3test/terrain/TerrainFractalGridTest.java
@@ -91,6 +91,10 @@ public class TerrainFractalGridTest extends SimpleApplication {
         this.mat_terrain.setTexture("region3ColorMap", rock);
         this.mat_terrain.setVector3("region3", new Vector3f(198, 260, this.rockScale));
 
+        // ROCK texture
+        this.mat_terrain.setTexture("region4ColorMap", rock);
+        this.mat_terrain.setVector3("region4", new Vector3f(198, 260, this.rockScale));
+
         this.mat_terrain.setTexture("slopeColorMap", rock);
         this.mat_terrain.setFloat("slopeTileFactor", 32);
 
diff --git a/engine/src/test/jme3test/terrain/TerrainGridTest.java b/engine/src/test/jme3test/terrain/TerrainGridTest.java
index 9b172b9a3..a38962c32 100644
--- a/engine/src/test/jme3test/terrain/TerrainGridTest.java
+++ b/engine/src/test/jme3test/terrain/TerrainGridTest.java
@@ -96,6 +96,9 @@ public class TerrainGridTest extends SimpleApplication {
         this.mat_terrain.setTexture("region3ColorMap", rock);
         this.mat_terrain.setVector3("region3", new Vector3f(198, 260, this.rockScale));
 
+        this.mat_terrain.setTexture("region4ColorMap", rock);
+        this.mat_terrain.setVector3("region4", new Vector3f(198, 260, this.rockScale));
+
         this.mat_terrain.setTexture("slopeColorMap", rock);
         this.mat_terrain.setFloat("slopeTileFactor", 32);