diff --git a/spec/index.bs b/spec/index.bs
index 6234bde859..01e259812c 100644
--- a/spec/index.bs
+++ b/spec/index.bs
@@ -1011,7 +1011,7 @@ dictionary GPURenderPassColorAttachmentDescriptor {
     GPUTextureView? resolveTarget = null;
 
     required GPULoadOp loadOp;
-    required GPUStoreOp storeOp;
+    required GPUStoreOp storeOp = "store";
     GPUColor clearColor;
 };
 </script>
@@ -1027,7 +1027,7 @@ dictionary GPURenderPassDepthStencilAttachmentDescriptor {
 
     required GPULoadOp depthLoadOp;
     required GPUStoreOp depthStoreOp;
-    required float clearDepth;
+    required float clearDepth = 1.0;
 
     required GPULoadOp stencilLoadOp;
     required GPUStoreOp stencilStoreOp;