diff --git a/fsl/data/dtifit.py b/fsl/data/dtifit.py
index 5820908e653609248304d87d2c8512b98b5f2364..eafc123cc3ea3582d4f357f376a6470bc81ea737 100644
--- a/fsl/data/dtifit.py
+++ b/fsl/data/dtifit.py
@@ -86,7 +86,7 @@ def getDTIFitDataPrefix(path):
     if len(prefixes) > 1:
         log.warning('Multiple dtifit prefixes detected: {}'.format(prefixes))
 
-    return op.basename(prefixes[0])
+    return op.basename(sorted(prefixes)[0])
 
 
 def isDTIFitPath(path):