diff --git a/lib/asterixpark/asterixpark.js b/lib/asterixpark/asterixpark.js
index 576bc836..5bc90068 100644
--- a/lib/asterixpark/asterixpark.js
+++ b/lib/asterixpark/asterixpark.js
@@ -128,7 +128,7 @@ class AsterixPark extends Park {
           } else if (ridetime.latency === 'FERME') {
             rideUpdateData.waitTime = -1;
           } else {
-            rideUpdateData.waitTime = parseInt(ridetime.latency, 10);
+            rideUpdateData.waitTime = parseInt(ridetime.latency, 10) || null;
 
             // add ride opening/closing time meta data (if available)
             if (ridetime.closing_time) {
diff --git a/lib/sixflags/sixflagsbase.js b/lib/sixflags/sixflagsbase.js
index a624e28f..ecd2b2d1 100644
--- a/lib/sixflags/sixflagsbase.js
+++ b/lib/sixflags/sixflagsbase.js
@@ -62,7 +62,7 @@ class SixFlagsPark extends Park {
           let rideStatus;
           if (ride.status === 'AttractionStatusOpen') {
             rideStatus = 'Operating';
-            rideWaitTime = parseInt(ride.waitTime, 10) || 0;
+            rideWaitTime = parseInt(ride.waitTime, 10) || null;
           } else if (ride.status === 'AttractionStatusClosed') {
             rideStatus = 'Closed';
           } else if (ride.status === 'AttractionStatusTemporarilyClosed') {
diff --git a/lib/testonline.js b/lib/testonline.js
index a27d5139..f8353d7a 100644
--- a/lib/testonline.js
+++ b/lib/testonline.js
@@ -90,9 +90,13 @@ function TestPark(park) {
       });
     });
 
-    it('should have a wait time for every ride', () => {
+    it('should have a wait time for every operating ride (or should be null)', () => {
       times.forEach((ride) => {
-        ValidateType(ride, 'waitTime', 'number');
+        if (ride.status === 'Operating') {
+          if (ride.waitTime !== null) {
+            ValidateType(ride, 'waitTime', 'number');
+          }
+        }
       });
     });