diff --git a/R/model-xgboost.R b/R/model-xgboost.R
index 583c4ec..38a8c7b 100644
--- a/R/model-xgboost.R
+++ b/R/model-xgboost.R
@@ -141,6 +141,12 @@ build_fit_formula_xgb <- function(parsedmodel) {
   } else if (objective %in% c("binary:logistic", "reg:logistic")) {
     assigned <- 1
     f <- expr(1 - 1 / (1 + exp(!!f + binomial()$linkfun(!!base_score))))
+  } else if (objective %in% c("count:poisson")) {
+    assigned <- 1
+    f <- expr(exp(!!f))
+  } else if (objective %in% c("reg:tweedie")) {
+    assigned <- 1
+    f <- expr(0.5 * exp(!!f)) ## I'm not sure why one has to multiply by 0.5, but it works.
   }
   if (assigned == 0) {
     stop("Only objectives 'binary:logistic', 'reg:squarederror', 'reg:logistic', 'binary:logitraw' are supported yet.")