diff --git a/src/cl/pyopencl-complex.h b/src/cl/pyopencl-complex.h
index 005ffab3dd68e5d08b8b48df02de9a5dd66a6c7b..d027df2945ff07f9347fd757ec15555b81aca991 100644
--- a/src/cl/pyopencl-complex.h
+++ b/src/cl/pyopencl-complex.h
@@ -24,6 +24,9 @@
 // functions as visible below, e.g. cdouble_log(z).
 //
 // Under the hood, the complex types are simply float2 and double2.
+// Note that native (operator-based) addition (float + float2) and
+// multiplication (float2*float1) is defined for these types,
+// but do not match the rules of complex arithmetic.
 
 #define PYOPENCL_DECLARE_COMPLEX_TYPE_INT(REAL_TP, REAL_3LTR, TPROOT, TP) \
   \