diff --git a/loopy/target/ispc.py b/loopy/target/ispc.py
index 20add6dfb32fa0d1d25461114286b43ca3fbcc35..3a3346198bb8448e571d922dfce31642f272a3e4 100644
--- a/loopy/target/ispc.py
+++ b/loopy/target/ispc.py
@@ -92,6 +92,7 @@ class LoopyISPCCodeMapper(LoopyCCodeMapper):
         if isinstance(ary, TemporaryVariable):
             gsize, lsize = self.kernel.get_grid_sizes_as_exprs()
             if lsize:
+                lsize, = lsize
                 from loopy.kernel.array import get_access_info
                 from pymbolic import evaluate