diff --git a/webgpu.h b/webgpu.h
index 909ec4c0..0b142a14 100644
--- a/webgpu.h
+++ b/webgpu.h
@@ -2455,6 +2455,12 @@ typedef struct WGPURenderPassDepthStencilAttachment {
      */
     WGPUStoreOp depthStoreOp;
     /**
+     * If NaN, indicates an `undefined` value (as defined by the JS spec).
+     * Use @ref WGPU_DEPTH_CLEAR_VALUE_UNDEFINED to indicate this semantically.
+     *
+     * NaN is determined by `isnan(depthClearValue) != 0`.
+     * (Do not use an equality check, because `NaN == NaN` is false.)
+     *
      * The `INIT` macro sets this to @ref WGPU_DEPTH_CLEAR_VALUE_UNDEFINED.
      */
     float depthClearValue;
diff --git a/webgpu.yml b/webgpu.yml
index ca9e714a..0bf293bc 100644
--- a/webgpu.yml
+++ b/webgpu.yml
@@ -2454,7 +2454,11 @@ structs:
         default: undefined
       - name: depth_clear_value
         doc: |
-          TODO
+          If NaN, indicates an `undefined` value (as defined by the JS spec).
+          Use @ref WGPU_DEPTH_CLEAR_VALUE_UNDEFINED to indicate this semantically.
+
+          NaN is determined by `isnan(depthClearValue) != 0`.
+          (Do not use an equality check, because `NaN == NaN` is false.)
         type: float32
         default: constant.depth_clear_value_undefined
       - name: depth_read_only