diff --git a/lib/codegen/meta/cdsl/types.py b/lib/codegen/meta/cdsl/types.py
index 3f2593fb78..c0e989e710 100644
--- a/lib/codegen/meta/cdsl/types.py
+++ b/lib/codegen/meta/cdsl/types.py
@@ -200,10 +200,15 @@ class IntType(LaneType):
     def __init__(self, bits):
         # type: (int) -> None
         assert bits > 0, 'IntType must have positive number of bits'
+        warning = ""
+        if bits < 32:
+            warning += "\nWARNING: "
+            warning += "arithmetic on {}bit integers is incomplete".format(
+                bits)
         super(IntType, self).__init__(
                 name='i{:d}'.format(bits),
                 membytes=bits // 8,
-                doc="An integer type with {} bits.".format(bits))
+                doc="An integer type with {} bits.{}".format(bits, warning))
         self.bits = bits
 
     def __repr__(self):