diff --git a/grudge/execution.py b/grudge/execution.py
index fade7fca37f92d728c2573c82f7af9a8c8cbcbdf..7e0a083569c589b8cc6645873f47a425955463c2 100644
--- a/grudge/execution.py
+++ b/grudge/execution.py
@@ -132,7 +132,7 @@ class ExecutionMapper(mappers.Evaluator,
 
         if isinstance(else_,  pyopencl.array.Array):
             sym_else = var("b")[i]
-        elif isinstance(then,  np.number):
+        elif isinstance(else_,  np.number):
             sym_else = var("b")
         else:
             raise TypeError(