diff --git a/sumpy/codegen.py b/sumpy/codegen.py
index 948512dfe884c35e0f421c4a4314796e38b0ab7b..61ed73014968d58a5455f006f4405f36d0d41572 100644
--- a/sumpy/codegen.py
+++ b/sumpy/codegen.py
@@ -705,7 +705,7 @@ def to_loopy_insns(assignments, vector_names=set(), pymbolic_expr_maps=[],
         result = [
                 lp.Assignment(id=None,
                     assignee=name, expression=convert_expr(name, expr),
-                    temp_var_type=lp.auto)
+                    temp_var_type=lp.Optional(None))
                 for name, expr in assignments]
 
     logger.info("loopy instruction generation: done")
diff --git a/sumpy/e2p.py b/sumpy/e2p.py
index d0d05cbf8c45e8d9f1c4552f784950bdfcab4bfb..7b0072ad55708ba205ceed3448914ad0d8eda281 100644
--- a/sumpy/e2p.py
+++ b/sumpy/e2p.py
@@ -119,7 +119,7 @@ class E2PBase(KernelCacheWrapper):
                     assignee="kernel_scaling",
                     expression=sympy_conv(
                         self.expansion.kernel.get_global_scaling_const()),
-                    temp_var_type=lp.auto)]
+                    temp_var_type=lp.Optional(None))]
 
     def get_cache_key(self):
         return (type(self).__name__, self.expansion, tuple(self.kernels))
diff --git a/sumpy/p2p.py b/sumpy/p2p.py
index 4c4eb945bb90d2d71bcb5ed3327d744e4ad26391..e3b457dd52e885bf66462e475b3b58edb78bd098 100644
--- a/sumpy/p2p.py
+++ b/sumpy/p2p.py
@@ -125,7 +125,7 @@ class P2PBase(KernelComputation, KernelCacheWrapper):
 
         return [lp.Assignment(id=None,
                     assignee="pair_result_%d" % i, expression=expr,
-                    temp_var_type=lp.auto)
+                    temp_var_type=lp.Optional(None))
                 for i, expr in enumerate(exprs)]
 
     def get_default_src_tgt_arguments(self):
diff --git a/sumpy/qbx.py b/sumpy/qbx.py
index 0d4359b6566e146d66f717d25c92569803893d0d..9708764c01d0448d7c7e8314efb461989c838acd 100644
--- a/sumpy/qbx.py
+++ b/sumpy/qbx.py
@@ -143,7 +143,7 @@ class LayerPotentialBase(KernelComputation, KernelCacheWrapper):
 
         return [lp.Assignment(id=None,
                     assignee="pair_result_%d" % i, expression=expr,
-                    temp_var_type=lp.auto)
+                    temp_var_type=lp.Optional(None))
                 for i, expr in enumerate(exprs)]
 
     def get_default_src_tgt_arguments(self):
diff --git a/sumpy/tools.py b/sumpy/tools.py
index c826ef2fe8ea4d3f96e3b8b816dd3500f5efaae8..863b4bb91749adef6ea65a374d697ecfa8d30bc4 100644
--- a/sumpy/tools.py
+++ b/sumpy/tools.py
@@ -299,7 +299,7 @@ class KernelComputation(object):
                 lp.Assignment(id=None,
                     assignee="knl_%d_scaling" % i,
                     expression=sympy_conv(kernel.get_global_scaling_const()),
-                    temp_var_type=dtype)
+                    temp_var_type=lp.Optional(dtype))
                 for i, (kernel, dtype) in enumerate(
                     zip(self.kernels, self.value_dtypes))]