diff --git a/sdk/lib/_http/http.dart b/sdk/lib/_http/http.dart
index 77a70d5a6b0..15597fcddcb 100644
--- a/sdk/lib/_http/http.dart
+++ b/sdk/lib/_http/http.dart
@@ -389,6 +389,7 @@ abstract interface class HttpHeaders {
   static const viaHeader = "via";
   static const warningHeader = "warning";
   static const wwwAuthenticateHeader = "www-authenticate";
+  static const contentDisposition = "content-disposition";
 
   // Cookie headers from RFC 6265.
   static const cookieHeader = "cookie";
@@ -429,7 +430,8 @@ abstract interface class HttpHeaders {
     retryAfterHeader,
     serverHeader,
     varyHeader,
-    wwwAuthenticateHeader
+    wwwAuthenticateHeader,
+    contentDisposition
   ];
 
   static const requestHeaders = [