diff --git a/loopy/kernel/tools.py b/loopy/kernel/tools.py
index 46b301b47c45430078f554a178448687eb490e94..cb72f283e2151fd8d097f19eb4e4876cc78ccd43 100644
--- a/loopy/kernel/tools.py
+++ b/loopy/kernel/tools.py
@@ -770,7 +770,8 @@ def assign_automatic_axes(kernel, axis=0, local_size=None):
         If *axis* is None, find a suitable axis automatically.
         """
         try:
-            desired_length = kernel.get_constant_iname_length(iname)
+            with isl.SuppressedWarnings(kernel.isl_context):
+                desired_length = kernel.get_constant_iname_length(iname)
         except isl.Error:
             # Likely unbounded, automatic assignment is not
             # going to happen for this iname.
@@ -882,7 +883,8 @@ def assign_automatic_axes(kernel, axis=0, local_size=None):
 
             def get_iname_length(iname):
                 try:
-                    return kernel.get_constant_iname_length(iname)
+                    with isl.SuppressedWarnings(kernel.isl_context):
+                        return kernel.get_constant_iname_length(iname)
                 except isl.Error:
                     return -1
             # assign longest auto axis inames first
diff --git a/setup.py b/setup.py
index 4fbb4e142b0680e28e88282409655c5a644a6f4e..ec03f82fa986babad881be80df47cf6ab3e51cc2 100644
--- a/setup.py
+++ b/setup.py
@@ -40,7 +40,7 @@ setup(name="loo.py",
           "pytools>=2016.1",
           "pymbolic>=2016.2",
           "cgen>=2016.1",
-          "islpy>=2016.1",
+          "islpy>=2016.1.2",
           "six>=1.8.0",
           ],