diff --git a/src/rt/rust_crate_cache.cpp b/src/rt/rust_crate_cache.cpp
index 3fdb33b9896b2ae1c12d2764c6f85c853b5e9133..3ab4a822e2ea889799397043235f2441f2b58606 100644
--- a/src/rt/rust_crate_cache.cpp
+++ b/src/rt/rust_crate_cache.cpp
@@ -49,7 +49,8 @@ rust_crate_cache::c_sym::c_sym(rust_dom *dom, lib *library, char const *name)
         DLOG(dom, cache, "resolved symbol '%s' to 0x%"  PRIxPTR,
                  name, val);
     } else {
-        DLOG_ERR(dom, cache, "unresolved symbol '%s', null lib handle", name);
+        DLOG_ERR(dom, cache, "unresolved symbol '%s', null lib handle\n"
+                             "(did you omit a -L flag?)", name);
     }
 }