diff --git a/src/compiler/compile/render_dom/Renderer.ts b/src/compiler/compile/render_dom/Renderer.ts
index 6de1c92f07..ffa293279b 100644
--- a/src/compiler/compile/render_dom/Renderer.ts
+++ b/src/compiler/compile/render_dom/Renderer.ts
@@ -22,6 +22,7 @@ export default class Renderer {
 	context: ContextMember[] = [];
 	context_lookup: Map<string, ContextMember> = new Map();
 	context_overflow: boolean;
+	is_update: Node;
 	blocks: Array<Block | Node | Node[]> = [];
 	readonly: Set<string> = new Set();
 	meta_bindings: Array<Node | Node[]> = []; // initial values for e.g. window.innerWidth, if there's a <svelte:window> meta tag
@@ -82,6 +83,9 @@ export default class Renderer {
 		);
 
 		this.context_overflow = this.context.length > 31;
+		this.is_update = this.context_overflow
+			? x`#dirty[0] !== -1`
+			: x`#dirty !== -1`;
 
 		// TODO messy
 		this.blocks.forEach(block => {
diff --git a/src/compiler/compile/render_dom/wrappers/Element/Binding.ts b/src/compiler/compile/render_dom/wrappers/Element/Binding.ts
index 7244d9203d..1ae6b0cd09 100644
--- a/src/compiler/compile/render_dom/wrappers/Element/Binding.ts
+++ b/src/compiler/compile/render_dom/wrappers/Element/Binding.ts
@@ -125,12 +125,8 @@ export default class BindingWrapper {
 			}
 
 			case 'textContent':
-				update_conditions.push(x`${this.snippet} !== ${parent.var}.textContent`);
-				mount_conditions.push(x`${this.snippet} !== void 0`);
-				break;
-
 			case 'innerHTML':
-				update_conditions.push(x`${this.snippet} !== ${parent.var}.innerHTML`);
+				update_conditions.push(x`${this.parent.renderer.is_update} && ${this.snippet} !== ${parent.var}.${this.node.name}`);
 				mount_conditions.push(x`${this.snippet} !== void 0`);
 				break;
 
diff --git a/src/compiler/compile/render_dom/wrappers/IfBlock.ts b/src/compiler/compile/render_dom/wrappers/IfBlock.ts
index dbf244b35f..6c3b8847db 100644
--- a/src/compiler/compile/render_dom/wrappers/IfBlock.ts
+++ b/src/compiler/compile/render_dom/wrappers/IfBlock.ts
@@ -500,7 +500,7 @@ export default class IfBlockWrapper extends Wrapper {
 
 	render_simple(
 		block: Block,
-		_parent_node: Identifier,
+		parent_node: Identifier,
 		_parent_nodes: Identifier,
 		dynamic,
 		{ name, anchor, if_exists_condition, has_transitions },
@@ -509,7 +509,8 @@ export default class IfBlockWrapper extends Wrapper {
 		const branch = this.branches[0];
 
 		if (branch.snippet) block.add_variable(branch.condition, branch.snippet);
-		block.add_variable(name);
+
+		let initial = null;
 
 		if (branch.dependencies.length > 0) {
 			const update_mount_node = this.get_update_mount_node(anchor);
@@ -569,8 +570,19 @@ export default class IfBlockWrapper extends Wrapper {
 			block.chunks.update.push(b`
 				if (${branch.condition}) ${name}.p(#ctx, #dirty);
 			`);
+		} else {
+			initial = x`${branch.block.name}(#ctx)`;
+
+			const initial_mount_node = parent_node || '#target';
+			const anchor_node = parent_node ? 'null' : 'anchor';
+
+			block.chunks.mount.push(
+				b`if (${name}) ${name}.m(${initial_mount_node}, ${anchor_node});`
+			);
 		}
 
+		block.add_variable(name, initial);
+
 		if (if_exists_condition) {
 			block.chunks.destroy.push(b`
 				if (${if_exists_condition}) ${name}.d(${detaching});