diff --git a/dist/client.js b/dist/client.js
index 310ecf1..41d63ec 100644
--- a/dist/client.js
+++ b/dist/client.js
@@ -142,7 +142,9 @@ class Client {
         this.client.onready = () => {
           clearTimeout(connectionTimeout);
           this._changeState(STATE_NOT_AUTHENTICATED);
-          this.updateCapability().then(() => resolve(this._capability));
+          // reject instead of leaving an unhandled rejection when the socket closes
+          // while CAPABILITY is pending (e.g. server greets and immediately drops the connection)
+          this.updateCapability().then(() => resolve(this._capability)).catch(reject);
         };
         this.client.onerror = err => {
           clearTimeout(connectionTimeout);
diff --git a/src/client.js b/src/client.js
index 4f0d3d7..d155dac 100644
--- a/src/client.js
+++ b/src/client.js
@@ -161,8 +161,11 @@ export default class Client {
         this.client.onready = () => {
           clearTimeout(connectionTimeout)
           this._changeState(STATE_NOT_AUTHENTICATED)
+          // reject instead of leaving an unhandled rejection when the socket closes
+          // while CAPABILITY is pending (e.g. server greets and immediately drops the connection)
           this.updateCapability()
             .then(() => resolve(this._capability))
+            .catch(reject)
         }
 
         this.client.onerror = (err) => {
diff --git a/src/client.unit.js b/src/client.unit.js
index fc1e1d3..f1886fa 100644
--- a/src/client.unit.js
+++ b/src/client.unit.js
@@ -60,6 +60,18 @@ describe('browserbox unit tests', () => {
         expect(br._capability[1]).to.equal('capa2')
       })
     })
+
+    it('should reject when CAPABILITY fails after greeting', () => {
+      const err = new Error('Socket closed unexpectedly!')
+      br.client.connect.returns(Promise.resolve())
+      br.client.enqueueCommand.callsFake(() => Promise.reject(err))
+      setTimeout(() => br.client.onready(), 0)
+      return br.openConnection().then(() => {
+        throw new Error('should not resolve')
+      }, (e) => {
+        expect(e).to.equal(err)
+      })
+    })
   })
 
   describe('#connect', () => {