diff --git a/NEWS.md b/NEWS.md
index 3aead75..67a95ba 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -2,6 +2,8 @@
 
 * flexdashboard now prevents top margin from being applied to boxes created with flexdashboard's markdown syntax when Bootstrap 5 is used. (#443)
 
+* Allow using `theme.preset` without needing to set `theme.bootswatch` to `null`. (#444)
+
 # flexdashboard 0.6.2
 
 ## New features
diff --git a/R/bslib.R b/R/bslib.R
index e5a522c..77a6778 100644
--- a/R/bslib.R
+++ b/R/bslib.R
@@ -24,7 +24,13 @@ resolve_theme <- function(theme) {
     # Default to cosmo theme (just like the non-bslib usage does)
     # (Users can explictly opt-out with bootswatch: default)
     if (!is_bs_theme(theme)) {
-      theme <- utils::modifyList(list(bootswatch = "cosmo"), theme)
+      theme_default <- list()
+      # bslib 0.5.1 added the "preset" option, which flexdashboard users may provide
+      # However, `preset` should not be set with `bootswatch`
+      if (packageVersion("bslib") < "0.5.1" && !"preset" %in% names(theme)) {
+        theme_default$bootswatch <- "cosmo"
+      }
+      theme <- utils::modifyList(theme_default, theme)
       theme <- do.call(bs_theme, theme)
     }
     # Also default to enable-rounded: true
diff --git a/README.md b/README.md
index 08ec5ca..6e9b123 100644
--- a/README.md
+++ b/README.md
@@ -89,8 +89,8 @@ rmarkdown::draft("dashboard.Rmd",
 
 There are two main places to get help with flexdashboard:
 
-- The [Posit
-  community](https://forum.posit.co/tag/flexdashboard)
+- The [RStudio
+  community](https://community.rstudio.com/tags/c/R-Markdown/10/flexdashboard)
   is a friendly place to ask any questions about flexdashboard. Be sure
   to use the `flexdashboard` tag. Add also the `shiny` tag is you are
   using a Shiny runtime.
diff --git a/tests/testthat/_snaps/format.md b/tests/testthat/_snaps/format.md
index 0c8052b..40ef941 100644
--- a/tests/testthat/_snaps/format.md
+++ b/tests/testthat/_snaps/format.md
@@ -9,11 +9,11 @@
       <h3>A wide plot</h3>
       <div class="knitr-options" data-fig-width="960" data-fig-height="480">
       </div>
-      <p><img src="data:image/png;base64,..." width="960" data-figure-id="fig1" /></p>
+      <p><img role="img" aria-label src="data:image/png;base64,..." alt width="960" data-figure-id="fig1" /></p>
       </div>
       <div id="a-tall-plot" class="section level3">
       <h3>A tall plot</h3>
       <div class="knitr-options" data-fig-width="480" data-fig-height="960">
       </div>
-      <p><img src="data:image/png;base64,..." width="480" data-figure-id="fig2" /></p>
+      <p><img role="img" aria-label src="data:image/png;base64,..." alt width="480" data-figure-id="fig2" /></p>