diff --git a/R/zzz.R b/R/zzz.R
index 64c49527..d3bdd695 100644
--- a/R/zzz.R
+++ b/R/zzz.R
@@ -10,3 +10,6 @@
                           "\nUse update.packages('ggplot2') to update.")
   }
 }
+.onLoad <- function(libname, pkgname) {
+  bayesplot_theme_set()
+}
diff --git a/tests/testthat/test-aesthetics.R b/tests/testthat/test-aesthetics.R
index f9e7599a..21b054de 100644
--- a/tests/testthat/test-aesthetics.R
+++ b/tests/testthat/test-aesthetics.R
@@ -210,6 +210,18 @@ test_that("ggplot2::theme_set overrides bayesplot theme", {
   expect_identical(bayesplot_theme_get(), minimal)
 })
 
+test_that(".onLoad keeps ggplot theme and resets bayesplot theme", {
+  old <- ggplot2::theme_set(ggplot2::theme_minimal())
+  before <- ggplot2::theme_get()
+  bayesplot:::.onLoad()
+
+  expect_identical(bayesplot_theme_get(), default)
+  expect_equal(.bayesplot_theme_env$current, default)
+  expect_equal(ggplot2::theme_get(), before)
+  expect_equal(.bayesplot_theme_env$gg_current, before)
+  ggplot2::theme_set(old)
+})
+
 bayesplot_theme_set(bayesplot::theme_default())
 color_scheme_set()