diff --git a/scheme/cyclone/transforms.sld b/scheme/cyclone/transforms.sld
index 67ae34a0..8b9f90bc 100644
--- a/scheme/cyclone/transforms.sld
+++ b/scheme/cyclone/transforms.sld
@@ -512,6 +512,9 @@
      string-ref
      string-set!
      substring
+     make-bytevector
+     bytevector-length
+     bytevector?
      make-vector
      list->vector
      vector-length
@@ -578,6 +581,7 @@
                   set-cdr!
                   string-set!
                   string->symbol ;; Could be mistaken for an identifier
+                  make-bytevector
                   make-vector
                   ;; I/O must be done at runtime for side effects:
                   Cyc-stdout
diff --git a/scheme/eval.sld b/scheme/eval.sld
index e91d6e55..29bb8c92 100644
--- a/scheme/eval.sld
+++ b/scheme/eval.sld
@@ -243,6 +243,8 @@
       (list 'string-ref string-ref)
       (list 'string-set! string-set!)
       (list 'substring substring)
+      (list 'make-bytevector make-bytevector)
+      (list 'bytevector-length bytevector-length)
       (list 'make-vector make-vector)
       (list 'list->vector list->vector)
       (list 'vector-length vector-length)
@@ -260,6 +262,7 @@
       (list 'procedure? procedure?)
       (list 'macro? macro?)
       (list 'vector? vector?)
+      (list 'bytevector? bytevector?)
       (list 'string? string?)
       (list 'symbol? symbol?)
       (list 'open-input-file open-input-file)