diff --git a/NEWS b/NEWS
index d0b0da358..82447e9f3 100644
--- a/NEWS
+++ b/NEWS
@@ -8,7 +8,7 @@ FEATURES
 *
 
 BUG FIXES and IMPROVEMENTS
-*
+* Updated CSS to specify `none` for `border` and `box-shadow` properties of `img` tags in leaflet. This avoids unexpected inheritance of these properties for example in `revealjs::revealjs_presentation`.
 
 
 
diff --git a/inst/htmlwidgets/lib/leaflet/leaflet.css b/inst/htmlwidgets/lib/leaflet/leaflet.css
index 230e5bad1..91b0db62e 100644
--- a/inst/htmlwidgets/lib/leaflet/leaflet.css
+++ b/inst/htmlwidgets/lib/leaflet/leaflet.css
@@ -48,6 +48,8 @@
 .leaflet-container img.leaflet-image-layer {
 	max-width: none !important;
 	max-height: none !important;
+	border: none;
+	box-shadow: none;
 	}
 
 .leaflet-container.leaflet-touch-zoom {