diff --git a/python/lsst/cp/verify/verifyLinearity.py b/python/lsst/cp/verify/verifyLinearity.py
index 33c0dd5..f7b4681 100644
--- a/python/lsst/cp/verify/verifyLinearity.py
+++ b/python/lsst/cp/verify/verifyLinearity.py
@@ -123,7 +123,7 @@ def amplifierStatistics(self, inputCalib, camera=None):
             outputStatistics[ampName]['FIT_RESIDUALS'] = inputCalib.fitResiduals[ampName].tolist()
             outputStatistics[ampName]['LINEAR_FIT'] = inputCalib.linearFit[ampName].tolist()
             outputStatistics[ampName]['LINEARITY_COEFFS'] = inputCalib.linearityCoeffs[ampName].tolist()
-            outputStatistics[ampName]['LINEARITY_TYPE'] = inputCalib.linearityType[ampName]
+            outputStatistics[ampName]['LINEARITY_TYPE'] = str(inputCalib.linearityType[ampName])
             if inputCalib.linearityType[ampName] == 'LookupTable':
                 outputStatistics[ampName]['TABLE_DATA'] = inputCalib.tableData[ampName].tolist()
         return outputStatistics