diff --git a/R/R/prophet.R b/R/R/prophet.R
index 74ab976..fd971a9 100644
--- a/R/R/prophet.R
+++ b/R/R/prophet.R
@@ -1262,6 +1262,13 @@ fit.prophet <- function(m, df, ...) {
     )
     args <- utils::modifyList(args, list(...))
     stan.fit <- do.call(rstan::optimizing, args)
+    if (stan.fit$return_code != 0) {
+      message(
+        'Optimization terminated abnormally. Falling back to Newton optimizer.'
+      )
+      args$algorithm = 'Newton'
+      stan.fit <- do.call(rstan::optimizing, args)
+    }
     m$params <- stan.fit$par
     n.iteration <- 1
   }
diff --git a/python/fbprophet/forecaster.py b/python/fbprophet/forecaster.py
index 11fdcda..ffb93de 100644
--- a/python/fbprophet/forecaster.py
+++ b/python/fbprophet/forecaster.py
@@ -1119,7 +1119,9 @@ class Prophet(object):
                 params = model.optimizing(**args)
             except RuntimeError:
                 # Fall back on Newton
-                logger.warning('Default optimization returns with an error. Falling back to Newton method.')
+                logger.warning(
+                    'Optimization terminated abnormally. Falling back to Newton.'
+                )
                 args['algorithm'] = 'Newton'
                 params = model.optimizing(**args)