--- a/src/compiler/aliencomp.lisp
+++ b/src/compiler/aliencomp.lisp
@@ -485,6 +485,8 @@
 
 (deftransform %sap-alien ((sap type) * * :important t)
   (give-up-ir1-transform
+   ;; FIXME: The hardcoded newline here causes more-than-usually
+   ;; screwed-up formatting of the optimization note output.
    "could not optimize away %SAP-ALIEN: forced to do runtime ~@
     allocation of alien-value structure"))