diff --git a/DESCRIPTION b/DESCRIPTION
index 20d8762..e6081f2 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: largeRCRF
 Type: Package
 Title: Large Random Competing Risks Forests
-Version: 1.0.3
+Version: 1.0.3.1
 Authors@R: c(
     person("Joel", "Therrien", email = "joel_therrien@sfu.ca", role = c("aut", "cre", "cph")),
     person("Jiguo", "Cao", email = "jiguo_cao@sfu.ca", role = c("aut", "dgs"))
diff --git a/R/cr_predictions.R b/R/cr_predictions.R
index 8c515f0..a2a982f 100644
--- a/R/cr_predictions.R
+++ b/R/cr_predictions.R
@@ -48,6 +48,10 @@ extractCIF <- function (x, event) {
 
 #' @export
 extractCIF.CompetingRiskFunctions <- function(x, event){
+  if(is.null(event) | anyNA(event)){
+    stop("event must be specified")
+  }
+  
   fun <- stats::stepfun(x$time.interest, c(0, x$cif[,event]))
   
   class(fun) <- "function"
@@ -57,6 +61,10 @@ extractCIF.CompetingRiskFunctions <- function(x, event){
 
 #' @export
 extractCIF.CompetingRiskFunctions.List <- function(x, event){
+  if(is.null(event) | anyNA(event)){
+    stop("event must be specified")
+  }
+  
   return(lapply(x, extractCIF.CompetingRiskFunctions, event))
 }
 
@@ -70,6 +78,10 @@ extractCHF <- function (x, event) {
 
 #' @export
 extractCHF.CompetingRiskFunctions <- function(x, event){
+  if(is.null(event) | anyNA(event)){
+    stop("event must be specified")
+  }
+  
   fun <- stats::stepfun(x$time.interest, c(0, x$chf[,event]))
   
   class(fun) <- "function"
@@ -79,6 +91,10 @@ extractCHF.CompetingRiskFunctions <- function(x, event){
 
 #' @export
 extractCHF.CompetingRiskFunctions.List <- function(x, event){
+  if(is.null(event) | anyNA(event)){
+    stop("event must be specified")
+  }
+  
   return(lapply(x, extractCHF.CompetingRiskFunctions, event))
 }