diff --git a/gpu/src/dawn.zig b/gpu/src/dawn.zig
index 85aa71ae..03219403 100644
--- a/gpu/src/dawn.zig
+++ b/gpu/src/dawn.zig
@@ -4,7 +4,7 @@ const TextureUsageFlags = @import("texture.zig").TextureUsageFlags;
 
 pub const CacheDeviceDescriptor = extern struct {
     chain: ChainedStruct,
-    isolation_key: [*:0]const u8,
+    isolation_key: [*:0]const u8 = "",
 };
 
 pub const EncoderInternalUsageDescriptor = extern struct {