diff --git a/test_problems/diamondSurf/run_diamond.py b/test_problems/diamondSurf/run_diamond.py
index 802297fe5..802d5add5 100644
--- a/test_problems/diamondSurf/run_diamond.py
+++ b/test_problems/diamondSurf/run_diamond.py
@@ -17,7 +17,7 @@ for n in range (20):
   x[ih] /= 1.4
   g.setState_TPX(t, p, x)
   # integrate the coverage equations to steady state
-  d.advanceCoverags(100.0)
+  d.advanceCoverages(100.0)
   cdot = d.netProductionRates(phase = dbulk) [0] #net rate of C(d production /m^2
   mdot = mw * cdot
   linear_rate = mdot/dbulk.density()