diff --git a/ezgui/src/backend_glow.rs b/ezgui/src/backend_glow.rs
index 54ac71d71f..41f9f248e4 100644
--- a/ezgui/src/backend_glow.rs
+++ b/ezgui/src/backend_glow.rs
@@ -1,9 +1,8 @@
 use crate::drawing::Uniforms;
 use crate::{Canvas, Color, ScreenDims, ScreenRectangle};
-use geom::{Angle, Polygon, Pt2D};
+use geom::Polygon;
 use glow::HasContext;
-use std::cell::{Cell, RefCell};
-use std::collections::{BTreeMap, HashMap};
+use std::cell::Cell;
 
 pub fn setup(
     window_title: &str,
@@ -60,6 +59,17 @@ pub fn setup(
         gl.use_program(Some(program));
 
         gl.enable(glow::SCISSOR_TEST);
+
+        gl.enable(glow::DEPTH_TEST);
+        gl.depth_func(glow::LEQUAL);
+
+        gl.enable(glow::BLEND);
+        gl.blend_func_separate(
+            glow::SRC_ALPHA,
+            glow::ONE_MINUS_SRC_ALPHA,
+            glow::SRC_ALPHA,
+            glow::ONE_MINUS_SRC_ALPHA,
+        );
     }
 
     let window_size = event_loop.primary_monitor().size();
@@ -90,6 +100,9 @@ impl<'a> GfxCtxInnards<'a> {
             Color::RGBA(r, g, b, a) => unsafe {
                 self.gl.clear_color(r, g, b, a);
                 self.gl.clear(glow::COLOR_BUFFER_BIT);
+
+                self.gl.clear_depth_f32(1.0);
+                self.gl.clear(glow::DEPTH_BUFFER_BIT);
             },
             _ => unreachable!(),
         }
diff --git a/ezgui/src/backend_wasm.rs b/ezgui/src/backend_wasm.rs
index 4f06227d1e..ba5f1292b1 100644
--- a/ezgui/src/backend_wasm.rs
+++ b/ezgui/src/backend_wasm.rs
@@ -81,6 +81,17 @@ pub fn setup(
         gl.use_program(Some(program));
 
         gl.enable(glow::SCISSOR_TEST);
+
+        gl.enable(glow::DEPTH_TEST);
+        gl.depth_func(glow::LEQUAL);
+
+        gl.enable(glow::BLEND);
+        gl.blend_func_separate(
+            glow::SRC_ALPHA,
+            glow::ONE_MINUS_SRC_ALPHA,
+            glow::SRC_ALPHA,
+            glow::ONE_MINUS_SRC_ALPHA,
+        );
     }
 
     (
@@ -109,6 +120,9 @@ impl<'a> GfxCtxInnards<'a> {
             Color::RGBA(r, g, b, a) => unsafe {
                 self.gl.clear_color(r, g, b, a);
                 self.gl.clear(glow::COLOR_BUFFER_BIT);
+
+                self.gl.clear_depth_f32(1.0);
+                self.gl.clear(glow::DEPTH_BUFFER_BIT);
             },
             _ => unreachable!(),
         }