diff --git a/R/vertmap.R b/R/vertmap.R
index 7e86a87..fd16f9e 100644
--- a/R/vertmap.R
+++ b/R/vertmap.R
@@ -52,7 +52,7 @@
 vertmap <- function(input = NULL, mapdatabase = "world", region = ".", 
                     geom = geom_point, jitter = NULL) {
 
-  if (!class(input) %in% c("list", "data.frame")) {
+  if (!inherits(input, c("list", "data.frame"))) {
     stop("Input must be of class list or data.frame", call. = FALSE)
   }
 	
diff --git a/R/yyy.R b/R/yyy.R
index 389072b..9a9132b 100644
--- a/R/yyy.R
+++ b/R/yyy.R
@@ -3,7 +3,7 @@ sw <- function(x) suppressWarnings(x)
 
 vertsumwrapper <- function(input = NULL, verbose = TRUE){
   
-  if (!class(input) %in% c("list", "data.frame")) {
+  if (!inherits(input, c("list", "data.frame"))) {
     stop("Input must be of class list or data.frame", call. = FALSE)
   }
   if (inherits(input, "list"))  input <- input$data