diff --git a/src/compiler/compile/render_dom/wrappers/KeyBlock.ts b/src/compiler/compile/render_dom/wrappers/KeyBlock.ts
index cbd021ff6c7..16acdab5da6 100644
--- a/src/compiler/compile/render_dom/wrappers/KeyBlock.ts
+++ b/src/compiler/compile/render_dom/wrappers/KeyBlock.ts
@@ -106,7 +106,7 @@ export default class KeyBlockWrapper extends Wrapper {
 			}
 			${this.var} = ${this.block.name}(#ctx);
 			${this.var}.c();
-			${has_transitions && b`@transition_in(${this.var})`}
+			${has_transitions && b`@transition_in(${this.var}, 1)`}
 			${this.var}.m(${this.get_update_mount_node(anchor)}, ${anchor});
 		`;