diff --git a/src/osgEarthDrivers/engine_rex/RexEngine.ImageLayer.glsl b/src/osgEarthDrivers/engine_rex/RexEngine.ImageLayer.glsl
index 6e952c1a85..ccd449badc 100644
--- a/src/osgEarthDrivers/engine_rex/RexEngine.ImageLayer.glsl
+++ b/src/osgEarthDrivers/engine_rex/RexEngine.ImageLayer.glsl
@@ -3,13 +3,6 @@
 #pragma vp_location   vertex_view
 #pragma vp_order      0.4
 
-#pragma import_defines(OE_MESA_23_WORKAROUND)
-#ifdef OE_MESA_23_WORKAROUND
-    #define TILE_COORDS gl_MultiTexCoord0
-#else
-    #define TILE_COORDS oe_layer_tilec
-#endif
-
 // Stage globals
 vec4 oe_layer_tilec;
 vec2 oe_layer_texc;
@@ -21,8 +14,8 @@ uniform mat4 oe_layer_texParentMatrix;
 void oe_rex_imageLayer_VS(inout vec4 vertexView)
 {
     // calculate the texture coordinates:
-    oe_layer_texc = (oe_layer_texMatrix * TILE_COORDS).st;
-    oe_layer_texcParent = (oe_layer_texParentMatrix * TILE_COORDS).st;
+    oe_layer_texc = (oe_layer_texMatrix * oe_layer_tilec).st;
+    oe_layer_texcParent = (oe_layer_texParentMatrix * oe_layer_tilec).st;
 }
 
 
diff --git a/src/osgEarthDrivers/engine_rex/RexEngine.vert.glsl b/src/osgEarthDrivers/engine_rex/RexEngine.vert.glsl
index 06aca1787b..5a4222f505 100644
--- a/src/osgEarthDrivers/engine_rex/RexEngine.vert.glsl
+++ b/src/osgEarthDrivers/engine_rex/RexEngine.vert.glsl
@@ -21,7 +21,12 @@ void oe_rex_init_model(inout vec4 vertexModel)
     oe_layer_tilec = gl_MultiTexCoord0;
 
     // Extract the vertex type marker
-    oe_terrain_vertexMarker = int(oe_layer_tilec.z);
+    //oe_terrain_vertexMarker = int(oe_layer_tilec.z);
+
+    // Doing this instead of the commented-out line above is a workaround
+    // for the Mesa driver bug described here:
+    // https://gitlab.freedesktop.org/mesa/mesa/-/issues/10482
+    oe_terrain_vertexMarker = int(gl_MultiTexCoord0.z);
 
     // Color of the underlying map geometry (untextured)
     vp_Color = oe_terrain_color;
diff --git a/src/osgEarthDrivers/engine_rex/RexTerrainEngineNode.cpp b/src/osgEarthDrivers/engine_rex/RexTerrainEngineNode.cpp
index ae1c5f76f6..c596db5e6b 100644
--- a/src/osgEarthDrivers/engine_rex/RexTerrainEngineNode.cpp
+++ b/src/osgEarthDrivers/engine_rex/RexTerrainEngineNode.cpp
@@ -260,6 +260,7 @@ RexTerrainEngineNode::onSetMap()
         _morphingSupported = false;
     }
 
+#if 0
     // There is an (apparent) bug in the mesa 23.1.4 driver that causes display artifacts 
     // when doing morphing; this code will attempt to detect that condition and disable
     // the offending code until we can find a workaround.
@@ -275,6 +276,7 @@ RexTerrainEngineNode::onSetMap()
             getOrCreateStateSet()->setDefine("OE_MESA_23_WORKAROUND");
         }
     }
+#endif
 
     // morphing imagery LODs requires we bind parent textures to their own unit.
     if (options.getMorphImagery() && _morphingSupported)