diff --git a/lib/go/test/Makefile.am b/lib/go/test/Makefile.am
index e93ec5c..b7ba870 100644
--- a/lib/go/test/Makefile.am
+++ b/lib/go/test/Makefile.am
@@ -32,6 +32,7 @@
 				TypedefFieldTest.thrift \
 				RefAnnotationFieldsTest.thrift \
 				UnionDefaultValueTest.thrift \
+				UnionBinaryTest.thrift \
 				ErrorTest.thrift \
 				NamesTest.thrift \
 				InitialismsTest.thrift \
@@ -50,6 +51,7 @@
 	$(THRIFT) $(THRIFTARGS) TypedefFieldTest.thrift
 	$(THRIFT) $(THRIFTARGS) RefAnnotationFieldsTest.thrift
 	$(THRIFT) $(THRIFTARGS) UnionDefaultValueTest.thrift
+	$(THRIFT) $(THRIFTARGS) UnionBinaryTest.thrift
 	$(THRIFT) $(THRIFTARGS) ErrorTest.thrift
 	$(THRIFT) $(THRIFTARGS) NamesTest.thrift
 	$(THRIFT) $(THRIFTARGS) InitialismsTest.thrift
@@ -74,7 +76,8 @@
 				namestest \
 				initialismstest \
 				dontexportrwtest \
-				ignoreinitialismstest
+				ignoreinitialismstest \
+				unionbinarytest
 	GOPATH=`pwd`/gopath $(GO) test thrift tests dontexportrwtest
 
 clean-local:
@@ -95,6 +98,7 @@
 	OptionalFieldsTest.thrift \
 	RefAnnotationFieldsTest.thrift \
 	UnionDefaultValueTest.thrift \
+	UnionBinaryTest.thrift \
 	ServicesTest.thrift \
 	TypedefFieldTest.thrift \
 	ErrorTest.thrift \
diff --git a/lib/go/test/UnionBinaryTest.thrift b/lib/go/test/UnionBinaryTest.thrift
new file mode 100644
index 0000000..f77112b
--- /dev/null
+++ b/lib/go/test/UnionBinaryTest.thrift
@@ -0,0 +1,25 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+# See https://issues.apache.org/jira/browse/THRIFT-4573
+union Sample {
+  1: map<string, string> u1,
+  2: binary u2,
+  3: list<string> u3
+}
diff --git a/lib/go/test/tests/union_binary_test.go b/lib/go/test/tests/union_binary_test.go
new file mode 100644
index 0000000..bdae2cb
--- /dev/null
+++ b/lib/go/test/tests/union_binary_test.go
@@ -0,0 +1,36 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package tests
+
+import (
+	"testing"
+	"unionbinarytest"
+)
+
+
+// See https://issues.apache.org/jira/browse/THRIFT-4573
+func TestUnionBinary(t *testing.T) {
+	s := unionbinarytest.NewSample()
+	s.U1 = map[string]string{}
+	s.U2 = []byte{}
+	if n := s.CountSetFieldsSample(); n != 2 {
+		t.Errorf("Expected 2 set fields, got %d!", n)
+	}
+}