diff --git a/packages/block-library/src/term-description/block.json b/packages/block-library/src/term-description/block.json
index 7a3f27c8063ab6..dc27fc17df7890 100644
--- a/packages/block-library/src/term-description/block.json
+++ b/packages/block-library/src/term-description/block.json
@@ -40,6 +40,18 @@
 		},
 		"interactivity": {
 			"clientNavigation": true
+		},
+		"__experimentalBorder": {
+			"radius": true,
+			"color": true,
+			"width": true,
+			"style": true,
+			"__experimentalDefaultControls": {
+				"radius": true,
+				"color": true,
+				"width": true,
+				"style": true
+			}
 		}
 	}
 }
diff --git a/packages/block-library/src/term-description/style.scss b/packages/block-library/src/term-description/style.scss
index bd455f7a68d3dd..1649a8d80c8f12 100644
--- a/packages/block-library/src/term-description/style.scss
+++ b/packages/block-library/src/term-description/style.scss
@@ -1,5 +1,7 @@
 // Lowest specificity on wrapper margins to avoid overriding layout styles.
 :where(.wp-block-term-description) {
+	// This block has customizable padding, border-box makes that more predictable.
+	box-sizing: border-box;
 	margin-top: var(--wp--style--block-gap);
 	margin-bottom: var(--wp--style--block-gap);
 }