diff --git a/ssl/test/runner/common.go b/ssl/test/runner/common.go
index 774c7a3..7aaf9a2 100644
--- a/ssl/test/runner/common.go
+++ b/ssl/test/runner/common.go
@@ -599,6 +599,10 @@
 	// server will send in the ServerHello. This does not affect the cipher
 	// the server believes it has actually negotiated.
 	SendCipherSuite uint16
+
+	// AppDataAfterChangeCipherSpec, if not null, causes application data to
+	// be sent immediately after ChangeCipherSpec.
+	AppDataAfterChangeCipherSpec []byte
 }
 
 func (c *Config) serverInit() {
diff --git a/ssl/test/runner/handshake_client.go b/ssl/test/runner/handshake_client.go
index 25fd7a8..f297fc1 100644
--- a/ssl/test/runner/handshake_client.go
+++ b/ssl/test/runner/handshake_client.go
@@ -840,6 +840,10 @@
 		c.writeRecord(recordTypeChangeCipherSpec, []byte{1})
 	}
 
+	if c.config.Bugs.AppDataAfterChangeCipherSpec != nil {
+		c.writeRecord(recordTypeApplicationData, c.config.Bugs.AppDataAfterChangeCipherSpec)
+	}
+
 	c.writeRecord(recordTypeHandshake, postCCSBytes)
 	return nil
 }
diff --git a/ssl/test/runner/handshake_server.go b/ssl/test/runner/handshake_server.go
index f811fb2..b61292e 100644
--- a/ssl/test/runner/handshake_server.go
+++ b/ssl/test/runner/handshake_server.go
@@ -819,6 +819,10 @@
 		c.writeRecord(recordTypeChangeCipherSpec, []byte{1})
 	}
 
+	if c.config.Bugs.AppDataAfterChangeCipherSpec != nil {
+		c.writeRecord(recordTypeApplicationData, c.config.Bugs.AppDataAfterChangeCipherSpec)
+	}
+
 	c.writeRecord(recordTypeHandshake, postCCSBytes)
 
 	c.cipherSuite = hs.suite.id
diff --git a/ssl/test/runner/runner.go b/ssl/test/runner/runner.go
index e298725..137a87c 100644
--- a/ssl/test/runner/runner.go
+++ b/ssl/test/runner/runner.go
@@ -632,6 +632,25 @@
 		damageFirstWrite: true,
 		flags:            []string{"-async"},
 	},
+	{
+		name: "AppDataAfterChangeCipherSpec",
+		config: Config{
+			Bugs: ProtocolBugs{
+				AppDataAfterChangeCipherSpec: []byte("TEST MESSAGE"),
+			},
+		},
+		shouldFail:    true,
+		expectedError: ":DATA_BETWEEN_CCS_AND_FINISHED:",
+	},
+	{
+		protocol: dtls,
+		name:     "AppDataAfterChangeCipherSpec-DTLS",
+		config: Config{
+			Bugs: ProtocolBugs{
+				AppDataAfterChangeCipherSpec: []byte("TEST MESSAGE"),
+			},
+		},
+	},
 }
 
 func doExchange(test *testCase, config *Config, conn net.Conn, messageLen int, isResume bool) error {
@@ -759,14 +778,21 @@
 		return err
 	}
 
-	if messageLen == 0 {
-		messageLen = 32
+	var testMessage []byte
+	if config.Bugs.AppDataAfterChangeCipherSpec != nil {
+		// We've already sent a message. Expect the shim to echo it
+		// back.
+		testMessage = config.Bugs.AppDataAfterChangeCipherSpec
+	} else {
+		if messageLen == 0 {
+			messageLen = 32
+		}
+		testMessage = make([]byte, messageLen)
+		for i := range testMessage {
+			testMessage[i] = 0x42
+		}
+		tlsConn.Write(testMessage)
 	}
-	testMessage := make([]byte, messageLen)
-	for i := range testMessage {
-		testMessage[i] = 0x42
-	}
-	tlsConn.Write(testMessage)
 
 	buf := make([]byte, len(testMessage))
 	if test.protocol == dtls {