diff --git a/dgl/OpenGL.hpp b/dgl/OpenGL.hpp
index 754614b3..c408b42c 100644
--- a/dgl/OpenGL.hpp
+++ b/dgl/OpenGL.hpp
@@ -31,7 +31,7 @@ ImageFormat asDISTRHOImageFormat(const GLenum format)
 {
     switch (format)
     {
-   #if defined(DGL_USE_OPENGL3) && !defined(DGL_USE_GLES2)
+   #if defined(DGL_USE_OPENGL3)
     case GL_RED:
    #else
     case GL_LUMINANCE:
@@ -58,7 +58,7 @@ GLenum asOpenGLImageFormat(const ImageFormat format)
     case kImageFormatNull:
         break;
     case kImageFormatGrayscale:
-       #if defined(DGL_USE_OPENGL3) && !defined(DGL_USE_GLES2)
+       #if defined(DGL_USE_OPENGL3)
         return GL_RED;
        #else
         return GL_LUMINANCE;
diff --git a/dgl/src/NanoVG.cpp b/dgl/src/NanoVG.cpp
index 47781cce..56546d76 100644
--- a/dgl/src/NanoVG.cpp
+++ b/dgl/src/NanoVG.cpp
@@ -89,6 +89,8 @@ DGL_EXT(PFNGLUNIFORMBLOCKBINDINGPROC,      glUniformBlockBinding)
 //#define STB_IMAGE_STATIC
 #if defined(DGL_USE_GLES2)
 # define NANOVG_GLES2_IMPLEMENTATION
+#elif defined(DGL_USE_GLES3)
+# define NANOVG_GLES3_IMPLEMENTATION
 #elif defined(DGL_USE_OPENGL3)
 # define NANOVG_GL3_IMPLEMENTATION
 #else
diff --git a/dgl/src/OpenGL3.cpp b/dgl/src/OpenGL3.cpp
index 9ef57c29..559badfa 100644
--- a/dgl/src/OpenGL3.cpp
+++ b/dgl/src/OpenGL3.cpp
@@ -48,6 +48,15 @@ START_NAMESPACE_DGL
 #if defined(DGL_USE_GLES2) && defined(DGL_USE_GLES3)
 # error Build config error, both GLESv2 and GLESv3 requested at the same time
 #endif
+#if defined(DGL_USE_GLES2) && !defined(DGL_USE_GLES)
+# error Build config error, DGL_USE_GLES2 is defined but DGL_USE_GLES is not
+#endif
+#if defined(DGL_USE_GLES3) && !defined(DGL_USE_GLES)
+# error Build config error, DGL_USE_GLES3 is defined but DGL_USE_GLES is not
+#endif
+#if defined(DGL_USE_GLES) && !(defined(DGL_USE_GLES2) || defined(DGL_USE_GLES3))
+# error Build config error, DGL_USE_GLES is defined which requires either DGL_USE_GLES2 or DGL_USE_GLES3
+#endif
 
 // --------------------------------------------------------------------------------------------------------------------
 
@@ -384,7 +393,7 @@ static void setupOpenGLImage(const OpenGLImage& image, GLuint textureId)
         intformat = GL_RGB;
         break;
     case kImageFormatGrayscale:
-       #if defined(DGL_USE_GLES3)
+       #if defined(DGL_USE_GLES)
         intformat = GL_R8;
        #elif defined(DGL_USE_OPENGL3)
         intformat = GL_RED;
@@ -422,18 +431,8 @@ static void setupOpenGLImage(const OpenGLImage& image, GLuint textureId)
     glBindTexture(GL_TEXTURE_2D, 0);
 }
 
-// static void drawOpenGLImage(const GraphicsContext& context,
-//                             const OpenGLImage& image,
-//                             const Point<int>& pos,
-//                             const GLuint textureId,
-//                             bool& setupCalled)
-// {
-// }
-
 void OpenGLImage::drawAt(const GraphicsContext& context, const Point<int>& pos)
 {
-    // drawOpenGLImage(context, *this, pos, textureId, setupCalled);
-
     if (textureId == 0 || isInvalid())
         return;
 
diff --git a/dgl/src/nanovg/nanovg_gl.h b/dgl/src/nanovg/nanovg_gl.h
index 7493134b..d905fedc 100644
--- a/dgl/src/nanovg/nanovg_gl.h
+++ b/dgl/src/nanovg/nanovg_gl.h
@@ -852,9 +852,9 @@ static int glnvg__renderCreateTexture(void* uptr, int type, int w, int h, int im
 		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
 		break;
 	default:
-#if defined(NANOVG_GLES2) || defined (NANOVG_GL2)
+#if defined (NANOVG_GL2)
 		glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, w, h, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, data);
-#elif defined(NANOVG_GLES3)
+#elif defined(NANOVG_GLES2) || defined(NANOVG_GLES3)
 		glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, w, h, 0, GL_RED, GL_UNSIGNED_BYTE, data);
 #else
 		glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, w, h, 0, GL_RED, GL_UNSIGNED_BYTE, data);
@@ -972,7 +972,7 @@ static int glnvg__renderUpdateTexture(void* uptr, int image, int x, int y, int w
 		glTexSubImage2D(GL_TEXTURE_2D, 0, x,y, w,h, GL_RGBA, GL_UNSIGNED_BYTE, data);
 		break;
 	default:
-#if defined(NANOVG_GLES2) || defined(NANOVG_GL2)
+#if defined(NANOVG_GL2)
 		glTexSubImage2D(GL_TEXTURE_2D, 0, x,y, w,h, GL_LUMINANCE, GL_UNSIGNED_BYTE, data);
 #else
 		glTexSubImage2D(GL_TEXTURE_2D, 0, x,y, w,h, GL_RED, GL_UNSIGNED_BYTE, data);