diff --git a/src/runtime/internal/transitions.ts b/src/runtime/internal/transitions.ts
index 3fc2cb1b00..33b35e4c51 100644
--- a/src/runtime/internal/transitions.ts
+++ b/src/runtime/internal/transitions.ts
@@ -89,10 +89,10 @@ export function create_in_transition(node: Element & ElementCSSInlineStyle, fn:
 			easing = linear,
 			tick = noop,
 			css,
-			staticCss,
+			static_css
 		} = config || null_transition;
 
-		if (staticCss) static_class_name = create_static_rule(node, staticCss, uid++);
+		if (static_css) static_class_name = create_static_rule(node, static_css, uid++);
 		if (css) animation_name = create_rule(node, 0, 1, duration, delay, easing, css, uid++);
 		tick(0, 1);
 
@@ -272,7 +272,7 @@ export function create_bidirectional_transition(node: Element & ElementCSSInline
 			easing = linear,
 			tick = noop,
 			css,
-			staticCss
+			static_css
 		} = config || null_transition;
 
 		const program = {
@@ -291,8 +291,8 @@ export function create_bidirectional_transition(node: Element & ElementCSSInline
 		} else {
 			// if this is an intro, and there's a delay, we need to do
 			// an initial tick and/or apply CSS animation immediately
-			if (staticCss && !static_class_name) {
-				static_class_name = create_static_rule(node, staticCss);
+			if (static_css && !static_class_name) {
+				static_class_name = create_static_rule(node, static_css);
 			}
 			if (css) {
 				clear_animation();
diff --git a/src/runtime/transition/index.ts b/src/runtime/transition/index.ts
index 49124914dc..911d558718 100644
--- a/src/runtime/transition/index.ts
+++ b/src/runtime/transition/index.ts
@@ -4,11 +4,11 @@ import { assign, is_function } from 'svelte/internal';
 export type EasingFunction = (t: number) => number;
 
 export interface TransitionConfig {
+	static_css?: string;
 	delay?: number;
 	duration?: number;
 	easing?: EasingFunction;
 	css?: (t: number, u: number) => string;
-	staticCss?: string;
 	tick?: (t: number, u: number) => void;
 }
 
@@ -117,17 +117,16 @@ export function slide(node: Element, {
 	const border_bottom_width = parseFloat(style.borderBottomWidth);
 
 	let displayOverride = '';
-	// May want to use a whitelist instead
 	if (style.display.includes('table')) {
 		displayOverride = 'display: block;';
 	}
 
 	return {
-		// Support a custom className to be added before and cleaned up after the thing.
-		staticCss: displayOverride + 'overflow: hidden;',
 		delay,
 		duration,
 		easing,
+		static_css: displayOverride +
+			'overflow: hidden;',
 		css: t =>
 			`opacity: ${Math.min(t * 20, 1) * opacity};` +
 			`height: ${t * height}px;` +