diff --git a/renderdoc/data/glsl/quadwrite.frag b/renderdoc/data/glsl/quadwrite.frag
index 305515fca..67b769a40 100644
--- a/renderdoc/data/glsl/quadwrite.frag
+++ b/renderdoc/data/glsl/quadwrite.frag
@@ -42,7 +42,7 @@
 // descriptor set will be patched from 0 to whichever descriptor set we're using in code
 layout(set = 0, binding = 0, r32ui) uniform coherent uimage2DArray overdrawImage;
 #else // OPENGL and OPENGL_ES
-layout(binding = 0, r32ui) uniform PRECISION coherent uimage2DArray overdrawImage;
+layout(r32ui) uniform coherent uimage2DArray overdrawImage;
 #endif
 layout(early_fragment_tests) in;
 
diff --git a/renderdoc/driver/gl/gl_debug.cpp b/renderdoc/driver/gl/gl_debug.cpp
index 3a3d537be..ca28d3987 100644
--- a/renderdoc/driver/gl/gl_debug.cpp
+++ b/renderdoc/driver/gl/gl_debug.cpp
@@ -301,7 +301,18 @@ void GLReplay::InitDebugData()
 
   DebugData.fixedcolFragShader = DebugData.quadoverdrawFragShader = 0;
 
-  if(glesShadersAreComplete && HasExt[ARB_shader_image_load_store] && HasExt[ARB_gpu_shader5])
+  if(IsGLES)
+  {
+    // quad overdraw not supported on GLES.
+    // 1.
+    //   dFdx doesn't support uints - potentially workaroundable with float casts, but highly
+    //   doubtful GLES compilers will do that properly without exploding.
+    // 2.
+    //   quad overdraw write shader must be linked with user shaders in program, which requires
+    //   matching ESSL version and features required for it aren't exposed as extensions to older
+    //   versions but only in core versions.
+  }
+  else if(HasExt[ARB_shader_image_load_store] && HasExt[ARB_gpu_shader5])
   {
     GenerateGLSLShader(fs, shaderType, "", GetEmbeddedResource(glsl_quadresolve_frag), glslBaseVer);
 
diff --git a/renderdoc/driver/gl/gl_overlay.cpp b/renderdoc/driver/gl/gl_overlay.cpp
index 1e4d1623a..8f5f4982d 100644
--- a/renderdoc/driver/gl/gl_overlay.cpp
+++ b/renderdoc/driver/gl/gl_overlay.cpp
@@ -213,12 +213,12 @@ ResourceId GLReplay::RenderOverlay(ResourceId texid, CompType typeHint, DebugOve
     DebugData.fixedcolFragShader = CreateShader(eGL_FRAGMENT_SHADER, sources);
   }
 
-  // this is not supported on GLES shading language 100
-  if(shaderType == eShaderGLSL || glslVer >= 300)
+  // this is not supported on GLES
+  if(shaderType == eShaderGLSL)
   {
     std::string defines = "";
 
-    if(glslVer < 450)
+    if(GLCoreVersion < 45)
     {
       // dFdx fine functions not available before GLSL 450. Use normal dFdx, which might be coarse,
       // so won't show quad overdraw properly
@@ -227,16 +227,20 @@ ResourceId GLReplay::RenderOverlay(ResourceId texid, CompType typeHint, DebugOve
 
       RDCWARN("Quad overdraw requires GLSL 4.50 for dFd(xy)fine, using possibly coarse dFd(xy).");
     }
+    else
+    {
+      glslVer = 450;
+    }
 
     std::vector<std::string> sources;
     GenerateGLSLShader(sources, shaderType, defines, GetEmbeddedResource(glsl_quadwrite_frag),
-                       glslVer);
+                       glslVer, false);
     DebugData.quadoverdrawFragShader = CreateShader(eGL_FRAGMENT_SHADER, sources);
   }
   else
   {
     if(overlay == DebugOverlay::QuadOverdrawDraw || overlay == DebugOverlay::QuadOverdrawPass)
-      RDCWARN("Quad overdraw shader not supported on GLES with %d shader", glslVer);
+      RDCWARN("Quad overdraw not supported on GLES", glslVer);
   }
 
   // we bind the separable program created for each shader, and copy
@@ -1316,6 +1320,12 @@ ResourceId GLReplay::RenderOverlay(ResourceId texid, CompType typeHint, DebugOve
           drv.glUseProgram(DebugData.overlayProg);
           drv.glBindProgramPipeline(0);
 
+          GLint loc = drv.glGetUniformLocation(DebugData.overlayProg, "overdrawImage");
+          if(loc != -1)
+            drv.glUniform1ui(loc, 0);
+          else
+            RDCERR("Couldn't get location of overdrawImage");
+
           drv.glBindFramebuffer(eGL_READ_FRAMEBUFFER, curdrawfbo);
           SafeBlitFramebuffer(0, 0, texDetails.width, texDetails.height, 0, 0, texDetails.width,
                               texDetails.height, GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT,