diff --git a/src/map.tsx b/src/map.tsx
index 71670b4e4..31c01e265 100644
--- a/src/map.tsx
+++ b/src/map.tsx
@@ -237,10 +237,10 @@ export default class ReactMapboxGl extends React.Component<Props & Events, State
       const didFitBoundsUpdate = (
         fitBounds !== nextProps.fitBounds || // Check for reference equality
         nextProps.fitBounds.length !== (fitBounds && fitBounds.length) || // Added element
-        !!fitBounds.find((c, i) => { // Check for equality
+        !!fitBounds.filter((c, i) => { // Check for equality
           const nc = nextProps.fitBounds && nextProps.fitBounds[i];
           return c[0] !== (nc && nc[0]) || c[1] !== (nc && nc[1]);
-        })
+        })[0]
       );
 
       if (didFitBoundsUpdate) {
diff --git a/src/util/diff.ts b/src/util/diff.ts
index 9d2a6739a..2272adc68 100644
--- a/src/util/diff.ts
+++ b/src/util/diff.ts
@@ -1,7 +1,7 @@
 const reduce = require('reduce-object'); // tslint:disable-line
 
 const find = (obj: any, predicate: (...args: any[]) => boolean) => (
-  Object.keys(obj).find((key) => predicate(obj[key], key))
+  Object.keys(obj).filter((key) => predicate(obj[key], key))[0]
 );
 
 const diff = (obj1: any, obj2: any) => (
diff --git a/tsconfig.json b/tsconfig.json
index dd0b9faf5..47e730588 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -2,7 +2,7 @@
   "compilerOptions": {
     "outDir": "lib",
     "module": "commonjs",
-    "target": "es6",
+    "target": "es5",
     "sourceMap": true,
     "moduleResolution": "node",
     "rootDirs": ["src"],