diff --git a/main.c b/main.c
index 5cf92e2..ccb5fe8 100644
--- a/main.c
+++ b/main.c
@@ -3848,6 +3848,8 @@ extern bool profiling;
 #else
 bool profiling;
 #endif
+#else
+const bool show_devtools = false;
 #endif
 
 Color debug_color = {1,0,0,1};
diff --git a/threedee.glsl b/threedee.glsl
index b44fda7..e1a212c 100644
--- a/threedee.glsl
+++ b/threedee.glsl
@@ -48,6 +48,13 @@ float decodeDepth(vec4 rgba) {
 }
 
 float do_shadow_sample(sampler2D shadowMap, vec2 uv, float scene_depth) {
+	{
+		//WebGL does not support GL_CLAMP_TO_BORDER, or border colors at all it seems, so we have to check explicitly.
+		//This will probably slow down other versions which do support texture borders, but the current system does
+		// not provide a non-overly complex way to include/not-include this code based on the backend. So here it is.
+		if (uv.x < 0.0 || uv.x > 1.0 || uv.y < 0.0 || uv.y > 1.0)
+			return 1.0;
+	}
 	float map_depth = decodeDepth(texture(shadowMap, uv));
 	map_depth += 0.001;//bias to counter self-shadowing
     return step(scene_depth, map_depth);
diff --git a/web_specific_shader_header.glsl b/web_specific_shader_header.glsl
new file mode 100644
index 0000000..16a0ba9
--- /dev/null
+++ b/web_specific_shader_header.glsl
@@ -0,0 +1,5 @@
+@block clamp_to_border
+	//WebGL does not support GL_CLAMP_TO_BORDER, or border colors at all it seems, so we have to check explicitly.
+	if (uv.x < 0.0 || uv.x > 1.0 || uv.y < 0.0 || uv.y > 1.0)
+		return 1.0;
+@end
\ No newline at end of file