diff --git a/DESCRIPTION b/DESCRIPTION
index 523eac2..b244a94 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -29,4 +29,4 @@ Suggests:
     testthat
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.2.3
+RoxygenNote: 7.2.3.9000
diff --git a/NEWS.md b/NEWS.md
index ace4446..2a61195 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,8 @@
 # mlr3batchmark (development version)
 
+* docs: A warning is now given when the loaded mlr3 version differs from the
+mlr3 version stored in the trained learners
+
 # mlr3batchmark 0.1.1
 
 * feat: `mlr3batchmark` now depends on package `batchtools` to avoid having to load `batchtools` explicitly.
diff --git a/R/reduceResultsBatchmark.R b/R/reduceResultsBatchmark.R
index 7f9359c..04e9212 100644
--- a/R/reduceResultsBatchmark.R
+++ b/R/reduceResultsBatchmark.R
@@ -29,6 +29,8 @@ reduceResultsBatchmark = function(ids = NULL, store_backends = TRUE, reg = batch
   tabs = split(tabs, by = "job.name")
   bmr = mlr3::BenchmarkResult$new()
 
+  version_checked = FALSE
+
   for (tab in tabs) {
     job = batchtools::makeJob(tab$job.id[1L], reg = reg)
     bmr_tasks = bmr$tasks
@@ -60,6 +62,17 @@ reduceResultsBatchmark = function(ids = NULL, store_backends = TRUE, reg = batch
     }
 
     results = batchtools::reduceResultsList(tab$job.id, reg = reg)
+
+    if (!version_checked) {
+      version_checked = TRUE
+      if (mlr3::mlr_reflections$package_version != results[[1]]$learner_state$mlr3_version) {
+        lg$warn(paste(sep = "\n",
+          "The mlr3 version (%s) from one of the trained learners differs from the currently loaded mlr3 version (%s).",
+          "This can lead to unexpected behavior and we recommend using the same versions of all mlr3 packages for collecting the results."),
+          results[[1]]$learner_state$mlr3_version, mlr3::mlr_reflections$package_version)
+      }
+    }
+
     rdata = mlr3::ResultData$new(data.table(
       task = list(task),
       learner = list(learner),
diff --git a/R/zzz.R b/R/zzz.R
index 0c21cd1..1693865 100644
--- a/R/zzz.R
+++ b/R/zzz.R
@@ -4,3 +4,8 @@
 #' @rawNamespace import(batchtools, except = chunk)
 #' @importFrom uuid UUIDgenerate
 "_PACKAGE"
+
+
+.onLoad = function(libname, pkgname) {
+  assign("lg", lgr::get_logger(pkgname), envir = parent.env(environment()))
+}
diff --git a/tests/testthat/test_reduceResultsBatchmark.R b/tests/testthat/test_reduceResultsBatchmark.R
index f7d27bb..f565764 100644
--- a/tests/testthat/test_reduceResultsBatchmark.R
+++ b/tests/testthat/test_reduceResultsBatchmark.R
@@ -31,3 +31,19 @@ test_that("reduceResultsBatchmark", {
   expect_data_table(tab, nrow = 4)
   expect_set_equal(tab$resampling_id, ids(resamplings))
 })
+
+test_that("warning is given when mlr3 versions mismatch", {
+  mlr_reflections = mlr3::mlr_reflections
+  mlr3_version = mlr_reflections$package_version
+  reg = makeExperimentRegistry(NA)
+  batchmark(benchmark_grid(tsk("mtcars"), lrn("regr.featureless"), rsmp("holdout")))
+  submitJobs()
+  waitForJobs()
+
+  on.exit({mlr_reflections$package_version = mlr3_version}, add = TRUE)
+
+  mlr_reflections$package_version = "100.0.0"
+
+  capture.output(reduceResultsBatchmark(reg = reg))
+  expect_true(grepl("The mlr3 version", lg$last_event$msg, fixed = TRUE))
+})