diff --git a/lib/minimap-find-and-replace-binding.js b/lib/minimap-find-and-replace-binding.js
index 57c834c..c426a9a 100644
--- a/lib/minimap-find-and-replace-binding.js
+++ b/lib/minimap-find-and-replace-binding.js
@@ -9,8 +9,8 @@ class MinimapFindAndReplaceBinding {
 		this.fnrVisible = fnrVisible
 		this.editor = this.minimap.getTextEditor()
 		this.subscriptions = new CompositeDisposable()
-		this.decorationsByMarkerId = {}
-		this.subscriptionsByMarkerId = {}
+		this.decorationsByMarkerId = new Map()
+		this.subscriptionsByMarkerId = new Map()
 
 		this.layer = this.fnrAPI.resultsMarkerLayerForTextEditor(this.editor)
 
@@ -23,20 +23,22 @@ class MinimapFindAndReplaceBinding {
 		this.discoverMarkers()
 	}
 
-	destroy () {
-		let id
-		for (id in this.subscriptionsByMarkerId) {
-			const sub = this.subscriptionsByMarkerId[id]; sub.dispose()
+	disposeMarkerSubsctiotions () {
+		const markerSubscriptions = this.subscriptionsByMarkerId.values()
+		for (const markerSubscription of markerSubscriptions) {
+			markerSubscription.dispose()
 		}
-		for (id in this.decorationsByMarkerId) {
-			const decoration = this.decorationsByMarkerId[id]; decoration.destroy()
+		const decorationSubscriotions = this.decorationsByMarkerId.values()
+		for (const decorationSubscriotion of decorationSubscriotions) {
+			decorationSubscriotion.destroy()
 		}
+	}
 
+	destroy () {
 		this.subscriptions.dispose()
+		this.clear()
 		this.minimap = null
 		this.editor = null
-		this.decorationsByMarkerId = {}
-		this.subscriptionsByMarkerId = {}
 	}
 
 	changeVisible (visible) {
@@ -49,23 +51,15 @@ class MinimapFindAndReplaceBinding {
 	}
 
 	clear () {
-		let id
-		for (id in this.subscriptionsByMarkerId) {
-			const sub = this.subscriptionsByMarkerId[id]
-			sub.dispose()
-			delete this.subscriptionsByMarkerId[id]
-		}
-
-		for (id in this.decorationsByMarkerId) {
-			const decoration = this.decorationsByMarkerId[id]
-			decoration.destroy()
-			delete this.decorationsByMarkerId[id]
-		}
+		this.disposeMarkerSubsctiotions()
+		this.decorationsByMarkerId.clear()
+		this.subscriptionsByMarkerId.clear()
 	}
 
 	discoverMarkers () {
 		setImmediate(() => {
-			for (const marker of this.layer.getMarkers()) {
+			const markers = this.layer.getMarkers()
+			for (const marker of markers) {
 				this.createDecoration(marker)
 			}
 		})
@@ -75,7 +69,7 @@ class MinimapFindAndReplaceBinding {
 		if (!this.findViewIsVisible()) {
 			return
 		}
-		if (this.decorationsByMarkerId[marker.id]) {
+		if (this.decorationsByMarkerId.has(marker.id)) {
 			return
 		}
 
@@ -89,15 +83,14 @@ class MinimapFindAndReplaceBinding {
 			return
 		}
 
-		const {
-			id,
-		} = marker
-		this.decorationsByMarkerId[id] = decoration
-		this.subscriptionsByMarkerId[id] = decoration.onDidDestroy(() => {
-			this.subscriptionsByMarkerId[id].dispose()
-			delete this.decorationsByMarkerId[id]
-			delete this.subscriptionsByMarkerId[id]
-		})
+		const { id } = marker
+		this.decorationsByMarkerId.set(id, decoration)
+		this.subscriptionsByMarkerId.set(id,
+			decoration.onDidDestroy(() => {
+				this.subscriptionsByMarkerId.get(id).dispose()
+				this.subscriptionsByMarkerId.delete(id)
+			}),
+		)
 	}
 
 	findViewIsVisible () {
diff --git a/lib/minimap-find-and-replace.js b/lib/minimap-find-and-replace.js
index ec5d962..f8670d2 100644
--- a/lib/minimap-find-and-replace.js
+++ b/lib/minimap-find-and-replace.js
@@ -8,11 +8,11 @@ module.exports = {
 		return this.active
 	},
 
-	activate (state) {
+	activate () {
 		this.active = false
 		this.fnrVisible = false
-		this.bindingsById = {}
-		this.subscriptionsById = {}
+		this.bindingsById = new Map()
+		this.subscriptionsById = new Map()
 		this.subscriptions = new CompositeDisposable()
 		require('atom-package-deps').install('minimap-find-and-replace')
 	},
@@ -46,23 +46,23 @@ module.exports = {
 					MinimapFindAndReplaceBinding = require('./minimap-find-and-replace-binding')
 				}
 
-				const {
-					id,
-				} = minimap
+				const { id } = minimap
 				const binding = new MinimapFindAndReplaceBinding(minimap, fnr, this.fnrVisible)
-				this.bindingsById[id] = binding
-
-				this.subscriptionsById[id] = minimap.onDidDestroy(() => {
-					if (this.subscriptionsById[id]) {
-						this.subscriptionsById[id].dispose()
-					}
-					if (this.bindingsById[id]) {
-						this.bindingsById[id].destroy()
-					}
-
-					delete this.bindingsById[id]
-					delete this.subscriptionsById[id]
-				})
+				this.bindingsById.set(id, binding)
+
+				this.subscriptionsById.set(id,
+					minimap.onDidDestroy(() => {
+						if (this.subscriptionsById.has(id)) {
+							this.subscriptionsById.get(id).dispose()
+						}
+						if (this.bindingsById.has(id)) {
+							this.bindingsById.get(id).destroy()
+						}
+
+						this.bindingsById.delete(id)
+						this.subscriptionsById.delete(id)
+					}),
+				)
 			}))
 		})
 	},
@@ -87,13 +87,13 @@ module.exports = {
 
 	changeVisible (visible) {
 		this.fnrVisible = visible
-		for (const id in this.bindingsById) {
-			this.bindingsById[id].changeVisible(visible)
+		const bindings = this.bindingsById.values()
+		for (const binding of bindings) {
+			binding.changeVisible(visible)
 		}
 	},
 
 	deactivatePlugin () {
-		let id
 		if (!this.active) {
 			return
 		}
@@ -101,11 +101,14 @@ module.exports = {
 		this.active = false
 		this.subscriptions.dispose()
 
-		for (id in this.subscriptionsById) {
-			const sub = this.subscriptionsById[id]; sub.dispose()
+		const subscriptions = this.subscriptionsById.values()
+		for (const subscription of subscriptions) {
+			subscription.dispose()
 		}
-		for (id in this.bindingsById) {
-			const binding = this.bindingsById[id]; binding.destroy()
+
+		const bindings = this.bindingsById.values()
+		for (const binding of bindings) {
+			binding.destroy()
 		}
 
 		this.bindingsById = {}
diff --git a/styles/minimap-find-and-replace.less b/styles/minimap-find-and-replace.less
index 2f7f62b..dd81010 100644
--- a/styles/minimap-find-and-replace.less
+++ b/styles/minimap-find-and-replace.less
@@ -6,5 +6,6 @@
 @import "syntax-variables";
 
 .minimap .search-result {
+  contain: layout size paint style;
   background: @syntax-result-marker-color-selected;
 }