diff --git a/code/nel/src/3d/driver/opengl/CMakeLists.txt b/code/nel/src/3d/driver/opengl/CMakeLists.txt
index 21d790668..8b5aabeb1 100644
--- a/code/nel/src/3d/driver/opengl/CMakeLists.txt
+++ b/code/nel/src/3d/driver/opengl/CMakeLists.txt
@@ -30,6 +30,14 @@ ELSE()
   SET(NLDRV_OGL_LIB "nel_drv_opengl")
 ENDIF()
 
+# This helps to debug issue 310
+IF(DEBUG_OGL_SPECULAR_FALLBACK)
+  ADD_DEFINITIONS(-DDEBUG_OGL_SPECULAR_FALLBACK)
+ENDIF()
+IF(DEBUG_OGL_COMBINE43_DISABLE)
+  ADD_DEFINITIONS(-DDEBUG_OGL_COMBINE43_DISABLE)
+ENDIF()
+
 NL_TARGET_DRIVER(${NLDRV_OGL_LIB} ${SRC})
 
 INCLUDE_DIRECTORIES(${OPENGL_INCLUDE_DIR} ${CMAKE_CURRENT_SOURCE_DIR})
diff --git a/code/nel/src/3d/driver/opengl/driver_opengl_extension.cpp b/code/nel/src/3d/driver/opengl/driver_opengl_extension.cpp
index 91a2fcab3..d386dd85f 100644
--- a/code/nel/src/3d/driver/opengl/driver_opengl_extension.cpp
+++ b/code/nel/src/3d/driver/opengl/driver_opengl_extension.cpp
@@ -786,7 +786,13 @@ static bool	setupNVTextureEnvCombine4(const char	*glext)
 {
 	H_AUTO_OGL(setupNVTextureEnvCombine4);
 	CHECK_EXT("GL_NV_texture_env_combine4");
+#ifdef DEBUG_OGL_COMBINE43_DISABLE
+	// issue 310: disable extension to debug bug around CDriverGL::setupSpecularPass()
+	nlwarning("GL_NV_texture_env_combine4 disabled by request (DEBUG_OGL_COMBINE43_DISABLE)");
+	return false;
+#else
 	return true;
+#endif
 }
 
 // *********************************
@@ -802,7 +808,13 @@ static bool	setupATITextureEnvCombine3(const char	*glext)
 // #endif
 
 	CHECK_EXT("GL_ATI_texture_env_combine3");
+#ifdef DEBUG_OGL_COMBINE43_DISABLE
+	// issue 310: disable extension to debug bug around CDriverGL::setupSpecularPass()
+	nlwarning("GL_ATI_texture_env_combine3 disabled by request (DEBUG_OGL_COMBINE43_DISABLE)");
+	return false;
+#else
 	return true;
+#endif
 }
 
 // *********************************
diff --git a/code/nel/src/3d/driver/opengl/driver_opengl_material.cpp b/code/nel/src/3d/driver/opengl/driver_opengl_material.cpp
index bf9845103..e28521310 100644
--- a/code/nel/src/3d/driver/opengl/driver_opengl_material.cpp
+++ b/code/nel/src/3d/driver/opengl/driver_opengl_material.cpp
@@ -1425,6 +1425,11 @@ void			CDriverGL::setupSpecularPass(uint pass)
 		}
 		else
 		{
+// Disabled because of Intel GPU texture bug (issue 310)
+// CMake options to debug
+// -DDEBUG_OGL_SPECULAR_FALLBACK=ON enables this
+// -DDEBUG_OGL_COMBINE43_DISABLE=ON disables GL_NV_texture_env_combine4/GL_ATI_texture_env_combine3
+#ifdef DEBUG_OGL_SPECULAR_FALLBACK
 			// Multiply texture1 by alpha_texture0 and display with add
 			_DriverGLStates.enableBlend(true);
 			_DriverGLStates.blendFunc(GL_ONE, GL_ONE);
@@ -1457,6 +1462,7 @@ void			CDriverGL::setupSpecularPass(uint pass)
 			}
 
 			activateTexEnvMode(1, env);
+#endif // DEBUG_OGL_SPECULAR_FALLBACK
 		}
 	}
 }