diff --git a/objectifier.js b/objectifier.js
index 7663dd7..8298ec3 100644
--- a/objectifier.js
+++ b/objectifier.js
@@ -54,8 +54,8 @@ function process(node, options = {}) {
       if (result[child.selector]) {
         for (let i in body) {
           let object = result[child.selector];
-          if (stringifyImportant && object[i] && object[i].endsWith('!important')) {
-            if (body[i].endsWith('!important')) {
+          if (stringifyImportant && typeof object[i] === "string" && object[i].endsWith('!important')) {
+            if (typeof body[i] === "string" && body[i].endsWith('!important')) {
               object[i] = body[i]
             }
           } else {
diff --git a/test/objectifier.test.js b/test/objectifier.test.js
index 3d49a1e..39cc9e3 100644
--- a/test/objectifier.test.js
+++ b/test/objectifier.test.js
@@ -184,5 +184,22 @@ test('keeps last important with priority', () => {
   })
 })
 
+test('keeps last important with priority', () => {
+  let root = parse('a { vertical-align: 2px center; };a { vertical-align: 1px center; }')
+  equal(postcssJS.objectify(root, { stringifyImportant: true }), {
+    a: {
+      'verticalAlign': "1px center"
+    }
+  })
+})
+
+test('keeps last important with priority', () => {
+  let root = parse('a { vertical-align: 2px center !important; };a { vertical-align: 1px center; }')
+  equal(postcssJS.objectify(root, { stringifyImportant: true }), {
+    a: {
+      'verticalAlign': "2px center !important"
+    }
+  })
+})
 
 test.run()