diff --git a/components/script/dom/rtcicecandidate.rs b/components/script/dom/rtcicecandidate.rs
index 144ac9f7413..9eefcd35134 100644
--- a/components/script/dom/rtcicecandidate.rs
+++ b/components/script/dom/rtcicecandidate.rs
@@ -98,4 +98,14 @@ impl RTCIceCandidateMethods for RTCIceCandidate {
     fn GetUsernameFragment(&self) -> Option<DOMString> {
         self.username_fragment.clone()
     }
+
+    /// https://w3c.github.io/webrtc-pc/#dom-rtcicecandidate-tojson
+    fn ToJSON(&self) -> RTCIceCandidateInit {
+        RTCIceCandidateInit {
+            candidate: self.candidate.clone(),
+            sdpMid: self.sdp_m_id.clone(),
+            sdpMLineIndex: self.sdp_m_line_index.clone(),
+            usernameFragment: self.username_fragment.clone(),
+        }
+    }
 }
diff --git a/components/script/dom/webidls/RTCIceCandidate.webidl b/components/script/dom/webidls/RTCIceCandidate.webidl
index 3d0fdb006c7..538805c88db 100644
--- a/components/script/dom/webidls/RTCIceCandidate.webidl
+++ b/components/script/dom/webidls/RTCIceCandidate.webidl
@@ -22,7 +22,7 @@ interface RTCIceCandidate {
     // readonly attribute DOMString?              relatedAddress;
     // readonly attribute unsigned short?         relatedPort;
     readonly attribute DOMString?              usernameFragment;
-    // RTCIceCandidateInit toJSON();
+    RTCIceCandidateInit toJSON();
 };
 
 dictionary RTCIceCandidateInit {