diff --git a/R/launch.R b/R/launch.R
index 241796c..4ede6d8 100644
--- a/R/launch.R
+++ b/R/launch.R
@@ -20,8 +20,9 @@ run <- function(dataIn) {
 
   # process and return
   if (inherits(captured, "error")) {
+    call <- conditionCall(captured)
     msg <- conditionMessage(captured)
-    cat("Error in R script", .e$path, "\n", sQuote(msg), file = stderr())
+    cat("Error in R script", .e$path, "\n", sQuote(call), "\n", sQuote(msg), file = stderr())
     return(invisible(F))
   }
   .e$out$x <- if (is.null(temp)) {
diff --git a/index.js b/index.js
index f43b588..32125fe 100644
--- a/index.js
+++ b/index.js
@@ -29,9 +29,19 @@ R.prototype.call = function(_opts, _callback) {
   var opts = _.isFunction(_opts) ? {} : _opts;
   this.options.env.input = JSON.stringify([this.d, this.path, opts]);
   var child = child_process.spawn("Rscript", this.args, this.options);
-  child.stderr.on("data", callback);
+  var stdout = "";
+  var stderr = "";
+  child.stderr.on("data", function(d) {
+    stderr += d.toString();
+  });
   child.stdout.on("data", function(d) {
-    callback(null, JSON.parse(d));
+    stdout += d;
+  });
+  child.on("close", function(code) {
+    callback(
+      stderr ? stderr : null,
+      stdout ? JSON.parse(stdout) : {}
+    );
   });
 };