diff --git a/lib/gateway/Shard.js b/lib/gateway/Shard.js
index d3ff34056..a7a47d52e 100644
--- a/lib/gateway/Shard.js
+++ b/lib/gateway/Shard.js
@@ -126,11 +126,16 @@ class Shard extends EventEmitter {
             * @prop {String} message The debug message
             * @prop {Number} id The ID of the shard
             */
-            this.emit("debug", `Queueing reconnect in ${this.reconnectInterval}ms | Attempt ${this.connectAttempts}`, this.id);
-            setTimeout(() => {
+            if(this.sessionID) {
+                this.emit("debug", `Immediately reconnecting for potential resume | Attempt ${this.connectAttempts}`, this.id);
                 this.client.shards.connect(this);
-            }, this.reconnectInterval);
-            this.reconnectInterval = Math.min(Math.round(this.reconnectInterval * (Math.random() * 2 + 1)), 30000);
+            } else {
+                this.emit("debug", `Queueing reconnect in ${this.reconnectInterval}ms | Attempt ${this.connectAttempts}`, this.id);
+                setTimeout(() => {
+                    this.client.shards.connect(this);
+                }, this.reconnectInterval);
+                this.reconnectInterval = Math.min(Math.round(this.reconnectInterval * (Math.random() * 2 + 1)), 30000);
+            }
         } else if(!options.reconnect) {
             this.hardReset();
         }
@@ -1627,8 +1632,10 @@ class Shard extends EventEmitter {
                     err = new Error("Gateway received invalid message");
                 } else if(event.code === 4003) {
                     err = new Error("Not authenticated");
+                    this.sessionID = null;
                 } else if(event.code === 4004) {
                     err = new Error("Authentication failed");
+                    this.sessionID = null;
                     reconnect = false;
                     this.emit("error", new Error(`Invalid token: ${this.client.token}`));
                 } else if(event.code === 4005) {
@@ -1643,9 +1650,11 @@ class Shard extends EventEmitter {
                     err = new Error("Gateway connection was ratelimited");
                 } else if(event.code === 4010) {
                     err = new Error("Invalid shard key");
+                    this.sessionID = null;
                     reconnect = false;
                 } else if(event.code === 4011) {
                     err = new Error("Shard has too many guilds (>2500)");
+                    this.sessionID = null;
                     reconnect = false;
                 } else if(event.code === 1006) {
                     err = new Error("Connection reset by peer");
diff --git a/lib/gateway/ShardManager.js b/lib/gateway/ShardManager.js
index 4fcce7ea0..31171197c 100644
--- a/lib/gateway/ShardManager.js
+++ b/lib/gateway/ShardManager.js
@@ -19,7 +19,7 @@ class ShardManager extends Collection {
     }
 
     connect(shard) {
-        if(this.lastConnect <= Date.now() - 5000 && !this.find((shard) => shard.connecting)) {
+        if(shard.sessionID || (this.lastConnect <= Date.now() - 5000 && !this.find((shard) => shard.connecting))) {
             shard.connect();
             this.lastConnect = Date.now() + 7500;
         } else {