diff --git a/R/miscfun.R b/R/miscfun.R
index 3b05b45..d45ef28 100644
--- a/R/miscfun.R
+++ b/R/miscfun.R
@@ -33,12 +33,14 @@ nsgaMonitor <- function(object, number_objectives, ...) {
         "Iter: ", iter),
       xlim = range(fitness[, 1]), ylim = range(fitness[, 2]),
       xlab = "f_1", ylab = "f_2")
-    lines(first_front[, 1][order(first_front[, 1])],
-      first_front[, 2][order(first_front[, 1])],
-      xlim = range(first_front[, 1]),
-      ylim = range(first_front[, 2]),
-      xlab = "f_1", ylab = "f_2",
-      col = "red", type = "l", pch = 12, main = "Pareto Front")
+    if(!is.null(nrow(first_front)) && nrow(first_front) > 1) {
+    	lines(first_front[, 1][order(first_front[, 1])],
+      	first_front[, 2][order(first_front[, 1])],
+      	xlim = range(first_front[, 1]),
+      	ylim = range(first_front[, 2]),
+      	xlab = "f_1", ylab = "f_2",
+      	col = "red", type = "l", pch = 12, main = "Pareto Front")
+    }
     legend("topright", inset = c(-0.8, 0),
       legend = c("Population", "Pareto Optimal"), pch = c(19, NA),
       title = "Values", lwd = c(NA, 2),