diff --git a/fsl/data/atlases.py b/fsl/data/atlases.py
index ecb5f0af560888b6773c204a0110f5add78538b2..0f885e0046e01d988e9e66de5eaee6f355526c45 100644
--- a/fsl/data/atlases.py
+++ b/fsl/data/atlases.py
@@ -415,7 +415,7 @@ class LabelAtlas(Atlas):
         """
 
         voxelLoc = transform.transform([worldLoc], self.worldToVoxMat.T)[0]
-        voxelLoc = voxelLoc.round()
+        voxelLoc = [int(v) for v in voxelLoc.round()]
 
         if voxelLoc[0] <  0             or \
            voxelLoc[1] <  0             or \