diff --git a/R/LearnerClassifXgboost.R b/R/LearnerClassifXgboost.R
index d94e1045..5732da97 100644
--- a/R/LearnerClassifXgboost.R
+++ b/R/LearnerClassifXgboost.R
@@ -107,7 +107,7 @@ LearnerClassifXgboost = R6Class("LearnerClassifXgboost",
         maximize                    = p_lgl(default = NULL, special_vals = list(NULL), tags = "train"),
         min_child_weight            = p_dbl(0, default = 1, tags = c("train", "control")),
         missing                     = p_dbl(default = NA, tags = c("train", "predict"), special_vals = list(NA, NA_real_, NULL)),
-        monotone_constraints        = p_uty(default = 0, tags = c("train", "control"), custom_check = function(x) {  checkmate::check_integerish(x, lower = -1, upper = 1, any.missing = FALSE) }), # nolint
+        monotone_constraints        = p_uty(default = 0, tags = c("train", "control"), custom_check = crate(function(x) { checkmate::check_integerish(x, lower = -1, upper = 1, any.missing = FALSE) })), # nolint
         normalize_type              = p_fct(c("tree", "forest"), default = "tree", tags = "train"),
         nrounds                     = p_int(1L, tags = c("train", "hotstart")),
         nthread                     = p_int(1L, default = 1L, tags = c("train", "control", "threads")),
diff --git a/R/LearnerRegrXgboost.R b/R/LearnerRegrXgboost.R
index 57f74281..b9e917b0 100644
--- a/R/LearnerRegrXgboost.R
+++ b/R/LearnerRegrXgboost.R
@@ -82,7 +82,7 @@ LearnerRegrXgboost = R6Class("LearnerRegrXgboost",
         maximize                    = p_lgl(default = NULL, special_vals = list(NULL), tags = "train"),
         min_child_weight            = p_dbl(0, default = 1, tags = "train"),
         missing                     = p_dbl(default = NA, tags = c("train", "predict"), special_vals = list(NA, NA_real_, NULL)),
-        monotone_constraints        = p_uty(default = 0, tags = c("train", "control"), custom_check = function(x) { checkmate::check_integerish(x, lower = -1, upper = 1, any.missing = FALSE) }), # nolint
+        monotone_constraints        = p_uty(default = 0, tags = c("train", "control"), custom_check = crate(function(x) { checkmate::check_integerish(x, lower = -1, upper = 1, any.missing = FALSE) })), # nolint
         normalize_type              = p_fct(c("tree", "forest"), default = "tree", tags = "train"),
         nrounds                     = p_int(1L, tags = c("train", "hotstart")),
         nthread                     = p_int(1L, default = 1L, tags = c("train", "threads")),