diff --git a/basis/compiler/tree/propagation/known-words/known-words.factor b/basis/compiler/tree/propagation/known-words/known-words.factor
index eb36da6ba8..d158c931b3 100644
--- a/basis/compiler/tree/propagation/known-words/known-words.factor
+++ b/basis/compiler/tree/propagation/known-words/known-words.factor
@@ -9,6 +9,7 @@ combinators generic.math splitting fry locals classes.tuple
 alien.accessors classes.tuple.private slots.private definitions
 strings.private vectors hashtables generic quotations alien
 alien.data alien.data.private
+strings sbufs byte-arrays byte-vectors
 stack-checker.dependencies
 compiler.tree.comparisons
 compiler.tree.propagation.info
@@ -240,6 +241,18 @@ generic-comparison-ops [
     '[ _ swap interval>> <class/interval-info> ] "outputs" set-word-prop
 ] assoc-each
 
+{
+    { >array array }
+    { >vector vector }
+    { >string string }
+    { >sbuf sbuf }
+    { >byte-array byte-array }
+    { >byte-vector byte-vector }
+    { >hashtable hashtable }
+} [
+    '[ drop _ <class-info> ] "outputs" set-word-prop
+] assoc-each
+
 { numerator denominator }
 [ [ drop integer <class-info> ] "outputs" set-word-prop ] each