diff --git a/src/librustdoc/html/static/rustdoc.css b/src/librustdoc/html/static/rustdoc.css
index bc7507f9af8..5b336c37515 100644
--- a/src/librustdoc/html/static/rustdoc.css
+++ b/src/librustdoc/html/static/rustdoc.css
@@ -1116,10 +1116,7 @@ h3 > .collapse-toggle, h4 > .collapse-toggle {
 	font-size: 16px;
 	cursor: default;
 	position: absolute;
-	/* Themes will override the color here,
-	   but it's necessary to make it opaque */
-	background-color: #eee;
-	border: 1px solid #999;
+	border: 1px solid;
 }
 
 .important-traits-tooltip::after {
diff --git a/src/librustdoc/html/static/themes/ayu.css b/src/librustdoc/html/static/themes/ayu.css
index ae273c5dc39..b436997da58 100644
--- a/src/librustdoc/html/static/themes/ayu.css
+++ b/src/librustdoc/html/static/themes/ayu.css
@@ -395,8 +395,8 @@ pre.ignore:hover, .information:hover + pre.ignore {
 }
 
 .important-traits-tooltiptext {
-    background-color: #314559 !important;
-    border-color: #5c6773 !important;
+    background-color: #314559;
+    border-color: #5c6773;
 }
 
 #titles > div.selected {
diff --git a/src/librustdoc/html/static/themes/dark.css b/src/librustdoc/html/static/themes/dark.css
index cdfe01f216d..f4ca67f8540 100644
--- a/src/librustdoc/html/static/themes/dark.css
+++ b/src/librustdoc/html/static/themes/dark.css
@@ -338,8 +338,8 @@ pre.ignore:hover, .information:hover + pre.ignore {
 }
 
 .important-traits-tooltiptext {
-	background-color: #111 !important;
-	border-color: #777 !important;
+	background-color: #111;
+	border-color: #777;
 }
 
 #titles > div:not(.selected) {
diff --git a/src/librustdoc/html/static/themes/light.css b/src/librustdoc/html/static/themes/light.css
index 8ffb935a378..b5a0ba4775c 100644
--- a/src/librustdoc/html/static/themes/light.css
+++ b/src/librustdoc/html/static/themes/light.css
@@ -332,8 +332,8 @@ pre.ignore:hover, .information:hover + pre.ignore {
 }
 
 .important-traits-tooltiptext {
-	background-color: #eee !important;
-	border-color: #999 !important;
+	background-color: #eee;
+	border-color: #999;
 }
 
 #titles > div:not(.selected) {