diff --git a/src/python/geoclaw/dtopotools.py b/src/python/geoclaw/dtopotools.py
index 37abc634f..44c36fbbf 100644
--- a/src/python/geoclaw/dtopotools.py
+++ b/src/python/geoclaw/dtopotools.py
@@ -1069,7 +1069,7 @@ def containing_rect(self):
 
         """
 
-        extent = [numpy.infty, -numpy.infty, numpy.infty, -numpy.infty]
+        extent = [numpy.inf, -numpy.inf, numpy.inf, -numpy.inf]
         for subfault in self.subfaults:
             for corner in subfault.corners:
                 extent[0] = min(corner[0], extent[0])
diff --git a/src/python/geoclaw/topotools.py b/src/python/geoclaw/topotools.py
index 1c9690d8b..0cda2e0fa 100644
--- a/src/python/geoclaw/topotools.py
+++ b/src/python/geoclaw/topotools.py
@@ -386,8 +386,8 @@ def delta(self):
             if self.unstructured:
 
                 # Calculate the smallest spacing between grid points            
-                dx = numpy.infty
-                dy = numpy.infty
+                dx = numpy.inf
+                dy = numpy.inf
                 num_comparisons = self.x.shape[0] - 1
                 for i in range(self.x.shape[0]):
                     for j in range(num_comparisons):