diff --git a/Makefile b/Makefile
index fe2b3d97..12616e0e 100644
--- a/Makefile
+++ b/Makefile
@@ -44,6 +44,7 @@ samples:
 	@PATH=./bin:$$PATH; protoc --jsonschema_out=jsonschemas --proto_path=${PROTO_PATH} ${PROTO_PATH}/Proto2Required.proto || echo "No messages found (Proto2Required.proto)"
 	@PATH=./bin:$$PATH; protoc --jsonschema_out=jsonschemas --proto_path=${PROTO_PATH} ${PROTO_PATH}/Proto2NestedMessage.proto || echo "No messages found (Proto2NestedMessage.proto)"
 	@PATH=./bin:$$PATH; protoc --jsonschema_out=jsonschemas --proto_path=${PROTO_PATH} ${PROTO_PATH}/GoogleValue.proto || echo "No messages found (GoogleValue.proto)"
+	@PATH=./bin:$$PATH; protoc --jsonschema_out=jsonschemas --proto_path=${PROTO_PATH} ${PROTO_PATH}/OneOf.proto || echo "No messages found (OneOf.proto)"
 	@PATH=./bin:$$PATH; protoc --jsonschema_out=all_fields_required:jsonschemas --proto_path=${PROTO_PATH} ${PROTO_PATH}/Proto2NestedObject.proto || echo "No messages found (Proto2NestedObject.proto)"
 	@PATH=./bin:$$PATH; protoc -I /usr/include --jsonschema_out=jsonschemas --proto_path=${PROTO_PATH} ${PROTO_PATH}/WellKnown.proto || echo "No messages found (WellKnown.proto)"
 	@PATH=./bin:$$PATH; protoc --jsonschema_out=jsonschemas --proto_path=${PROTO_PATH} ${PROTO_PATH}/NoPackage.proto
diff --git a/internal/converter/converter_test.go b/internal/converter/converter_test.go
index 65665544..c7aadd54 100644
--- a/internal/converter/converter_test.go
+++ b/internal/converter/converter_test.go
@@ -285,6 +285,11 @@ func configureSampleProtos() map[string]sampleProto {
 			ProtoFileName:         "JSONFields.proto",
 			UseJSONFieldnamesOnly: true,
 		},
+		"OneOf": {
+			ExpectedJSONSchema: []string{testdata.OneOf},
+			FilesToGenerate:    []string{"OneOf.proto"},
+			ProtoFileName:      "OneOf.proto",
+		},
 	}
 }
 
diff --git a/internal/converter/testdata/message_kind_11.go b/internal/converter/testdata/message_kind_11.go
index 6529e54f..65616c3a 100644
--- a/internal/converter/testdata/message_kind_11.go
+++ b/internal/converter/testdata/message_kind_11.go
@@ -108,6 +108,23 @@ const MessageKind11 = `{
         }
     },
     "additionalProperties": true,
-    "type": "object"
+    "type": "object",
+    "oneOf": [
+        {
+            "required": [
+                "kind2"
+            ]
+        },
+        {
+            "required": [
+                "kind3"
+            ]
+        },
+        {
+            "required": [
+                "kind4"
+            ]
+        }
+    ]
 }
 `
diff --git a/internal/converter/testdata/message_kind_12.go b/internal/converter/testdata/message_kind_12.go
index 0743a51d..3b3f4ada 100644
--- a/internal/converter/testdata/message_kind_12.go
+++ b/internal/converter/testdata/message_kind_12.go
@@ -7,6 +7,7 @@ const MessageKind12 = `{
             "type": "string"
         },
         "f": {
+            "$schema": "http://json-schema.org/draft-04/schema#",
             "properties": {
                 "name": {
                     "type": "string"
@@ -113,7 +114,24 @@ const MessageKind12 = `{
                 }
             },
             "additionalProperties": true,
-            "type": "object"
+            "type": "object",
+            "oneOf": [
+                {
+                    "required": [
+                        "kind2"
+                    ]
+                },
+                {
+                    "required": [
+                        "kind3"
+                    ]
+                },
+                {
+                    "required": [
+                        "kind4"
+                    ]
+                }
+            ]
         },
         "kind5": {
             "properties": {
@@ -189,6 +207,23 @@ const MessageKind12 = `{
         }
     },
     "additionalProperties": true,
-    "type": "object"
+    "type": "object",
+    "oneOf": [
+        {
+            "required": [
+                "kind5"
+            ]
+        },
+        {
+            "required": [
+                "kind6"
+            ]
+        },
+        {
+            "required": [
+                "kind7"
+            ]
+        }
+    ]
 }
 `
diff --git a/internal/converter/testdata/oneof.go b/internal/converter/testdata/oneof.go
new file mode 100644
index 00000000..13f523c0
--- /dev/null
+++ b/internal/converter/testdata/oneof.go
@@ -0,0 +1,39 @@
+package testdata
+
+const OneOf = `{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "properties": {
+        "bar": {
+            "properties": {
+                "foo": {
+                    "type": "integer"
+                }
+            },
+            "additionalProperties": true,
+            "type": "object"
+        },
+        "baz": {
+            "properties": {
+                "foo": {
+                    "type": "string"
+                }
+            },
+            "additionalProperties": true,
+            "type": "object"
+        }
+    },
+    "additionalProperties": true,
+    "type": "object",
+    "oneOf": [
+        {
+            "required": [
+                "bar"
+            ]
+        },
+        {
+            "required": [
+                "baz"
+            ]
+        }
+    ]
+}`
diff --git a/internal/converter/testdata/proto/OneOf.proto b/internal/converter/testdata/proto/OneOf.proto
new file mode 100644
index 00000000..df8163a0
--- /dev/null
+++ b/internal/converter/testdata/proto/OneOf.proto
@@ -0,0 +1,17 @@
+syntax="proto3";
+package samples;
+
+message OneOf {
+	oneof choice {
+		Bar bar = 1;
+		Baz baz = 2;
+	}
+
+	message Bar {
+		int32 foo = 1;
+	}
+	
+	message Baz {
+		string foo = 1;
+	}
+}
diff --git a/internal/converter/types.go b/internal/converter/types.go
index 89d1eda2..24ba6985 100644
--- a/internal/converter/types.go
+++ b/internal/converter/types.go
@@ -491,6 +491,11 @@ func (c *Converter) recursiveConvertMessageType(curPkg *ProtoPackage, msg *descr
 		}
 		c.logger.WithField("field_name", fieldDesc.GetName()).WithField("type", recursedJSONSchemaType.Type).Trace("Converted field")
 
+		// If this field is part of a OneOf declaration then build that here:
+		if fieldDesc.OneofIndex != nil {
+			jsonSchemaType.OneOf = append(jsonSchemaType.OneOf, &jsonschema.Type{Required: []string{fieldDesc.GetName()}})
+		}
+
 		// Figure out which field names we want to use:
 		switch {
 		case c.UseJSONFieldnamesOnly:
diff --git a/jsonschemas/MessageKind11.jsonschema b/jsonschemas/MessageKind11.jsonschema
index 19dd2f0a..2db73213 100644
--- a/jsonschemas/MessageKind11.jsonschema
+++ b/jsonschemas/MessageKind11.jsonschema
@@ -106,5 +106,22 @@
         }
     },
     "additionalProperties": true,
-    "type": "object"
+    "type": "object",
+    "oneOf": [
+        {
+            "required": [
+                "kind2"
+            ]
+        },
+        {
+            "required": [
+                "kind3"
+            ]
+        },
+        {
+            "required": [
+                "kind4"
+            ]
+        }
+    ]
 }
\ No newline at end of file
diff --git a/jsonschemas/MessageKind12.jsonschema b/jsonschemas/MessageKind12.jsonschema
index d2c9222d..51c1a7d8 100644
--- a/jsonschemas/MessageKind12.jsonschema
+++ b/jsonschemas/MessageKind12.jsonschema
@@ -5,6 +5,7 @@
             "type": "string"
         },
         "f": {
+            "$schema": "http://json-schema.org/draft-04/schema#",
             "properties": {
                 "name": {
                     "type": "string"
@@ -111,7 +112,24 @@
                 }
             },
             "additionalProperties": true,
-            "type": "object"
+            "type": "object",
+            "oneOf": [
+                {
+                    "required": [
+                        "kind2"
+                    ]
+                },
+                {
+                    "required": [
+                        "kind3"
+                    ]
+                },
+                {
+                    "required": [
+                        "kind4"
+                    ]
+                }
+            ]
         },
         "kind5": {
             "properties": {
@@ -187,5 +205,22 @@
         }
     },
     "additionalProperties": true,
-    "type": "object"
+    "type": "object",
+    "oneOf": [
+        {
+            "required": [
+                "kind5"
+            ]
+        },
+        {
+            "required": [
+                "kind6"
+            ]
+        },
+        {
+            "required": [
+                "kind7"
+            ]
+        }
+    ]
 }
\ No newline at end of file
diff --git a/jsonschemas/OneOf.jsonschema b/jsonschemas/OneOf.jsonschema
new file mode 100644
index 00000000..da8da4ad
--- /dev/null
+++ b/jsonschemas/OneOf.jsonschema
@@ -0,0 +1,37 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "properties": {
+        "bar": {
+            "properties": {
+                "foo": {
+                    "type": "integer"
+                }
+            },
+            "additionalProperties": true,
+            "type": "object"
+        },
+        "baz": {
+            "properties": {
+                "foo": {
+                    "type": "string"
+                }
+            },
+            "additionalProperties": true,
+            "type": "object"
+        }
+    },
+    "additionalProperties": true,
+    "type": "object",
+    "oneOf": [
+        {
+            "required": [
+                "bar"
+            ]
+        },
+        {
+            "required": [
+                "baz"
+            ]
+        }
+    ]
+}
\ No newline at end of file