diff --git a/scheme/read.sld b/scheme/read.sld
index 51cdba84..62f94087 100644
--- a/scheme/read.sld
+++ b/scheme/read.sld
@@ -18,7 +18,8 @@
   (inline
     Cyc-opaque-eq?
     Cyc-opaque-unsafe-eq?
-    Cyc-opaque-unsafe-string?)
+    Cyc-opaque-unsafe-string?
+    Cyc-opaque-unsafe-string->number)
   (begin
 
 (define-syntax include