diff --git a/app.R b/app.R
index aa5d93c..da94dcb 100644
--- a/app.R
+++ b/app.R
@@ -83,8 +83,8 @@ server <- function(input, output, session)
 
   # in bounds
   in_bounds <- reactive({
-    if (is.null(input$map_bounds))
-      return(communes[F,])
+    req(input$map_bounds)
+
     bounds <- input$map_bounds
     latrng <- range(bounds$north, bounds$south)
     lngrng <- range(bounds$east, bounds$west)
@@ -113,6 +113,8 @@ server <- function(input, output, session)
 
   # GHM
   data_ghm <- reactive({
+    req(input$slider_age, input$check_sexe, input$slider_date, in_bounds())
+
     GHM %>%
       filter(Age <= input$slider_age[2] & Age >= input$slider_age[1], 
              date_entree <= input$slider_date[2] & date_sortie >= input$slider_date[1],
@@ -124,7 +126,7 @@ server <- function(input, output, session)
     data_ghm() %>%
       count(GHM, Sexe) %>%
       semi_join(GHM %>% count(GHM) %>% top_n(10) %>% arrange(n), by = "GHM") %>%
-      ungroup %>%
+      ungroup() %>%
       mutate(GHM = GHM %>% factor(levels = GHM %>% unique)) %>%
       ggplot() +
       aes(x = GHM, y = n, fill = Sexe) +
@@ -137,6 +139,8 @@ server <- function(input, output, session)
 
   # Sexe
   data_sexe <- reactive({
+    req(input$slider_age, input$slider_date, in_bounds())
+
     if (input$choice_ghm %>% is.null)
     {
       GHM %>%
@@ -168,6 +172,8 @@ server <- function(input, output, session)
 
   # Age
   data_age <- reactive({
+    req(input$slider_date, input$check_sexe, in_bounds())
+
     if (input$choice_ghm %>% is.null)
     {
       GHM %>%