diff --git a/wgpu/src/shader/quad.wgsl b/wgpu/src/shader/quad.wgsl
index fb402158c7..023b5a6d1c 100644
--- a/wgpu/src/shader/quad.wgsl
+++ b/wgpu/src/shader/quad.wgsl
@@ -147,11 +147,11 @@ fn solid_fs_main(
 
 struct GradientVertexInput {
     @location(0) v_pos: vec2<f32>,
-    @location(1) colors_1: vec4<u32>,
-    @location(2) colors_2: vec4<u32>,
-    @location(3) colors_3: vec4<u32>,
-    @location(4) colors_4: vec4<u32>,
-    @location(5) offsets: vec4<u32>,
+    @location(1) @interpolate(flat) colors_1: vec4<u32>,
+    @location(2) @interpolate(flat) colors_2: vec4<u32>,
+    @location(3) @interpolate(flat) colors_3: vec4<u32>,
+    @location(4) @interpolate(flat) colors_4: vec4<u32>,
+    @location(5) @interpolate(flat) offsets: vec4<u32>,
     @location(6) direction: vec4<f32>,
     @location(7) position_and_scale: vec4<f32>,
     @location(8) border_color: vec4<f32>,
@@ -161,11 +161,11 @@ struct GradientVertexInput {
 
 struct GradientVertexOutput {
     @builtin(position) position: vec4<f32>,
-    @location(1) colors_1: vec4<u32>,
-    @location(2) colors_2: vec4<u32>,
-    @location(3) colors_3: vec4<u32>,
-    @location(4) colors_4: vec4<u32>,
-    @location(5) offsets: vec4<u32>,
+    @location(1) @interpolate(flat) colors_1: vec4<u32>,
+    @location(2) @interpolate(flat) colors_2: vec4<u32>,
+    @location(3) @interpolate(flat) colors_3: vec4<u32>,
+    @location(4) @interpolate(flat) colors_4: vec4<u32>,
+    @location(5) @interpolate(flat) offsets: vec4<u32>,
     @location(6) direction: vec4<f32>,
     @location(7) position_and_scale: vec4<f32>,
     @location(8) border_color: vec4<f32>,
diff --git a/wgpu/src/shader/triangle.wgsl b/wgpu/src/shader/triangle.wgsl
index 9f512d1489..3a2b984555 100644
--- a/wgpu/src/shader/triangle.wgsl
+++ b/wgpu/src/shader/triangle.wgsl
@@ -38,22 +38,22 @@ fn solid_fs_main(input: SolidVertexOutput) -> @location(0) vec4<f32> {
 
 struct GradientVertexInput {
     @location(0) v_pos: vec2<f32>,
-    @location(1) colors_1: vec4<u32>,
-    @location(2) colors_2: vec4<u32>,
-    @location(3) colors_3: vec4<u32>,
-    @location(4) colors_4: vec4<u32>,
-    @location(5) offsets: vec4<u32>,
+    @location(1) @interpolate(flat) colors_1: vec4<u32>,
+    @location(2) @interpolate(flat) colors_2: vec4<u32>,
+    @location(3) @interpolate(flat) colors_3: vec4<u32>,
+    @location(4) @interpolate(flat) colors_4: vec4<u32>,
+    @location(5) @interpolate(flat) offsets: vec4<u32>,
     @location(6) direction: vec4<f32>,
 }
 
 struct GradientVertexOutput {
     @builtin(position) position: vec4<f32>,
     @location(0) raw_position: vec2<f32>,
-    @location(1) colors_1: vec4<u32>,
-    @location(2) colors_2: vec4<u32>,
-    @location(3) colors_3: vec4<u32>,
-    @location(4) colors_4: vec4<u32>,
-    @location(5) offsets: vec4<u32>,
+    @location(1) @interpolate(flat) colors_1: vec4<u32>,
+    @location(2) @interpolate(flat) colors_2: vec4<u32>,
+    @location(3) @interpolate(flat) colors_3: vec4<u32>,
+    @location(4) @interpolate(flat) colors_4: vec4<u32>,
+    @location(5) @interpolate(flat) offsets: vec4<u32>,
     @location(6) direction: vec4<f32>,
 }