diff --git a/pyqtgraph/functions.py b/pyqtgraph/functions.py
index fe3f9910..062986c7 100644
--- a/pyqtgraph/functions.py
+++ b/pyqtgraph/functions.py
@@ -1380,7 +1380,7 @@ def gaussianFilter(data, sigma):
         # clip off extra data
         sl = [slice(None)] * data.ndim
         sl[ax] = slice(filtered.shape[ax]-data.shape[ax],None,None)
-        filtered = filtered[sl]
+        filtered = filtered[tuple(sl)]
     return filtered + baseline