diff --git a/tests/nii.spec.js b/tests/nii.spec.js
index b7436fbb0..4358aa296 100644
--- a/tests/nii.spec.js
+++ b/tests/nii.spec.js
@@ -152,14 +152,17 @@ describe('NIFTI', function() {
     })
     validate.NIFTI(null, file, jsonContentsDict, {}, [], [], function(issues) {
       assert(
-        issues.some(issue => (
-          issue.reason === 'Invalid filetype: IntendedFor should point to the .nii[.gz] files.' &&
-          issue.evidence === 'func/sub-15_task-mixedeventrelatedprobe_run-05_bold.json'
-        )),
+        issues.some(
+          issue =>
+            issue.reason ===
+              'Invalid filetype: IntendedFor should point to the .nii[.gz] files.' &&
+            issue.evidence ===
+              'func/sub-15_task-mixedeventrelatedprobe_run-05_bold.json',
+        ),
       )
     })
   })
-  
+
   it('should generate warning if files listed in IntendedFor of fieldmap json do not exist', function() {
     var file = {
       name: 'sub-09_ses-test_run-01_fieldmap.nii.gz',
@@ -187,7 +190,7 @@ describe('NIFTI', function() {
     })
     validate.NIFTI(null, file, jsonContentsDict, {}, [], [], function(issues) {
       assert(
-        (issues.length === 3 && issues[0].code == 17 && issues[1].code == 37), 
+        issues.length === 3 && issues[0].code == 17 && issues[1].code == 37,
       )
     })
   })
diff --git a/validators/nifti/nii.js b/validators/nifti/nii.js
index 3d15b2d35..5c652c546 100644
--- a/validators/nifti/nii.js
+++ b/validators/nifti/nii.js
@@ -429,7 +429,7 @@ module.exports = function NIFTI(
         typeof mergedDictionary['IntendedFor'] == 'string'
           ? [mergedDictionary['IntendedFor']]
           : mergedDictionary['IntendedFor']
-      
+
       for (let key = 0; key < intendedFor.length; key++) {
         const intendedForFile = intendedFor[key]
         checkIfIntendedExists(intendedForFile, fileList, issues, file)
@@ -486,9 +486,11 @@ function checkIfIntendedExists(intendedForFile, fileList, issues, file) {
   let onTheList = false
 
   for (let key2 in fileList) {
-    const filePath = fileList[key2].relativePath
-    if (filePath === intendedForFileFull) {
-      onTheList = true
+    if (key2) {
+      const filePath = fileList[key2].relativePath
+      if (filePath === intendedForFileFull) {
+        onTheList = true
+      }
     }
   }
   if (!onTheList) {
@@ -519,8 +521,7 @@ function checkIfValidFiletype(intendedForFile, issues, file) {
       new Issue({
         file: file,
         code: 37,
-        reason:
-          `Invalid filetype: IntendedFor should point to the .nii[.gz] files.`,
+        reason: `Invalid filetype: IntendedFor should point to the .nii[.gz] files.`,
         evidence: intendedForFile,
       }),
     )