diff --git a/layout/style/CSS.cpp b/layout/style/CSS.cpp
index 81b67e23ab..f0cacef571 100644
--- a/layout/style/CSS.cpp
+++ b/layout/style/CSS.cpp
@@ -59,12 +59,6 @@ CSS::Supports(const GlobalObject& aGlobal,
     return false;
   }
 
-  if (info.mStyleBackendType == StyleBackendType::Servo) {
-    NS_ConvertUTF16toUTF8 property(aProperty);
-    NS_ConvertUTF16toUTF8 value(aValue);
-    return Servo_CSSSupports(&property, &value);
-  }
-
   nsCSSParser parser;
   return parser.EvaluateSupportsDeclaration(aProperty, aValue, info.mDocURI,
                                             info.mBaseURI, info.mPrincipal);
@@ -83,10 +77,6 @@ CSS::Supports(const GlobalObject& aGlobal,
     return false;
   }
 
-  if (info.mStyleBackendType == StyleBackendType::Servo) {
-    MOZ_CRASH("stylo: CSS.supports() with arguments is not yet implemented");
-  }
-
   nsCSSParser parser;
   return parser.EvaluateSupportsCondition(aCondition, info.mDocURI,
                                           info.mBaseURI, info.mPrincipal);