diff --git a/assets/trix/images/block_level_decrease.svg b/assets/trix/images/nesting_level_decrease.svg
similarity index 100%
rename from assets/trix/images/block_level_decrease.svg
rename to assets/trix/images/nesting_level_decrease.svg
diff --git a/assets/trix/images/block_level_increase.svg b/assets/trix/images/nesting_level_increase.svg
similarity index 100%
rename from assets/trix/images/block_level_increase.svg
rename to assets/trix/images/nesting_level_increase.svg
diff --git a/assets/trix/stylesheets/icons.scss b/assets/trix/stylesheets/icons.scss
index 587626bb..bbfc6e86 100644
--- a/assets/trix/stylesheets/icons.scss
+++ b/assets/trix/stylesheets/icons.scss
@@ -1,11 +1,11 @@
-$icon-block-level-decrease: svgo-data-uri('trix/images/block_level_decrease.svg', $precision: 1);
-$icon-block-level-increase: svgo-data-uri('trix/images/block_level_increase.svg', $precision: 1);
 $icon-bold: svgo-data-uri('trix/images/bold.svg', $precision: 1);
 $icon-bullets: svgo-data-uri('trix/images/bullets.svg', $precision: 0);
 $icon-code: svgo-data-uri('trix/images/code.svg', $precision: 1);
 $icon-heading-1: svgo-data-uri('trix/images/heading_1.svg', $precision: 0);
 $icon-italic: svgo-data-uri('trix/images/italic.svg', $precision: 1);
 $icon-link: svgo-data-uri('trix/images/link.svg', $precision: 2);
+$icon-nesting-level-decrease: svgo-data-uri('trix/images/nesting_level_decrease.svg', $precision: 1);
+$icon-nesting-level-increase: svgo-data-uri('trix/images/nesting_level_increase.svg', $precision: 1);
 $icon-numbers: svgo-data-uri('trix/images/numbers.svg', $precision: 1);
 $icon-quote: svgo-data-uri('trix/images/quote.svg', $precision: 0);
 $icon-redo: svgo-data-uri('trix/images/redo.svg', $precision: 1);
diff --git a/assets/trix/stylesheets/toolbar.scss b/assets/trix/stylesheets/toolbar.scss
index e0dd038d..b6c08d8b 100644
--- a/assets/trix/stylesheets/toolbar.scss
+++ b/assets/trix/stylesheets/toolbar.scss
@@ -80,9 +80,9 @@ trix-toolbar {
         &.numbers::before { background-image: $icon-numbers; }
         &.undo::before { background-image: $icon-undo; }
         &.redo::before { background-image: $icon-redo; }
-        &.nesting-level, &.block-level {
-          &.decrease::before { background-image: $icon-block-level-decrease; }
-          &.increase::before { background-image: $icon-block-level-increase }
+        &.nesting-level {
+          &.decrease::before { background-image: $icon-nesting-level-decrease; }
+          &.increase::before { background-image: $icon-nesting-level-increase; }
         }
 
         &.active::before {