diff --git a/lang/rust/src/resolver.sld b/lang/rust/src/resolver.sld
index 3b4e8c6..60710fc 100644
--- a/lang/rust/src/resolver.sld
+++ b/lang/rust/src/resolver.sld
@@ -554,7 +554,7 @@
                           ((1) (next-major parsed-version)))))))
        ; TODO: this implements the RFC 3493-style implicit prerelease stuff, I _think_
        ((<) (list (cons '< (exclude-prerelease parsed-version))))
-       ((<=) (list (cons '<= parsed-version)))
+       ((<=) (list (cons '< (first-incompatible parsed-version)))) ; TODO(puck): is this correct? how *should* "<= 3" be parsed.
        ((>) (list (cons '> parsed-version)))
        ((>=) (list (cons '>= parsed-version)))
        ((=) (list (cons '= parsed-version)))