diff --git a/NEWS.md b/NEWS.md
index 92a4d22..f545702 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,7 @@
 # htmlwidgets (development version)
 
+* htmlwidgets once again eagerly recurses into list-like objects when searching for JavaScript strings wrapped in `JS()`. If you encounter an infinite recursion ("C stack usage is too close to the limit"), the best strategy is to coerce the offending items to a character string. (#478)
+
 # htmlwidgets 1.6.3
 
 ### Potentially breaking changes
diff --git a/R/utils.R b/R/utils.R
index a43a5ad..ef582ea 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -161,7 +161,8 @@ JSEvals <- function(list) {
 #' @noRd
 #' @keywords internal
 shouldEval <- function(options) {
-  if (inherits(options, c("list", "data.frame"))) {
+  if (is.list(options)) {
+    if (inherits(options, "POSIXlt")) return(FALSE)
     if ((n <- length(options)) == 0) return(FALSE)
     # use numeric indices as names (remember JS indexes from 0, hence -1 here)
     if (is.null(names(options)))