diff --git a/src/idl_gen_json_schema.cpp b/src/idl_gen_json_schema.cpp
index e519415dd..7f98a6e6a 100644
--- a/src/idl_gen_json_schema.cpp
+++ b/src/idl_gen_json_schema.cpp
@@ -175,13 +175,14 @@ class JsonSchemaGenerator : public BaseGenerator {
         }          
         code_ += typeLine;
       }
+      code_ += "      },";  // close properties
+
       std::vector<FieldDef *> requiredProperties;
       std::copy_if(properties.begin(), properties.end(),
                    back_inserter(requiredProperties),
                    [](FieldDef const *prop) { return prop->required; });
       if (requiredProperties.size() > 0) {
-        code_ += "      },";  // close properties
-        std::string required_string("      \"required\" : [ ");
+        std::string required_string("      \"required\" : [");
         for (auto req_prop = requiredProperties.cbegin();
              req_prop != requiredProperties.cend();
              ++req_prop) {
@@ -190,12 +191,10 @@ class JsonSchemaGenerator : public BaseGenerator {
             required_string.append(", ");
           }
         }
-        required_string.append("]");
+        required_string.append("],");
         code_ += required_string;
-      } else {
-        code_ += "      }";  // close properties
       }
-
+      code_ += "      \"additionalProperties\" : false";
       std::string closeType("    }");
       if (*s != parser_.structs_.vec.back()) {
         closeType.append(",");
diff --git a/tests/monster_test.bfbs b/tests/monster_test.bfbs
index 843e308c5..15d399862 100644
Binary files a/tests/monster_test.bfbs and b/tests/monster_test.bfbs differ
diff --git a/tests/monster_test.schema.json b/tests/monster_test.schema.json
index 578e89645..62880abbc 100644
--- a/tests/monster_test.schema.json
+++ b/tests/monster_test.schema.json
@@ -16,42 +16,49 @@
     "MyGame_OtherNameSpace_Unused" : {
       "type" : "object",
       "properties" : {
-      }
+      },
+      "additionalProperties" : false
     },
     "MyGame_OtherNameSpace_TableB" : {
       "type" : "object",
       "properties" : {
         "a" : { "$ref" : "#/definitions/TableA" }
-      }
+      },
+      "additionalProperties" : false
     },
     "TableA" : {
       "type" : "object",
       "properties" : {
         "b" : { "$ref" : "#/definitions/MyGame_OtherNameSpace_TableB" }
-      }
+      },
+      "additionalProperties" : false
     },
     "MyGame_InParentNamespace" : {
       "type" : "object",
       "properties" : {
-      }
+      },
+      "additionalProperties" : false
     },
     "MyGame_Example2_Monster" : {
       "type" : "object",
       "properties" : {
-      }
+      },
+      "additionalProperties" : false
     },
     "MyGame_Example_Test" : {
       "type" : "object",
       "properties" : {
         "a" : { "type" : "number" },
         "b" : { "type" : "number" }
-      }
+      },
+      "additionalProperties" : false
     },
     "MyGame_Example_TestSimpleTableWithEnum" : {
       "type" : "object",
       "properties" : {
         "color" : { "$ref" : "#/definitions/MyGame_Example_Color" }
-      }
+      },
+      "additionalProperties" : false
     },
     "MyGame_Example_Vec3" : {
       "type" : "object",
@@ -62,14 +69,16 @@
         "test1" : { "type" : "number" },
         "test2" : { "$ref" : "#/definitions/MyGame_Example_Color" },
         "test3" : { "$ref" : "#/definitions/MyGame_Example_Test" }
-      }
+      },
+      "additionalProperties" : false
     },
     "MyGame_Example_Ability" : {
       "type" : "object",
       "properties" : {
         "id" : { "type" : "number" },
         "distance" : { "type" : "number" }
-      }
+      },
+      "additionalProperties" : false
     },
     "MyGame_Example_Stat" : {
       "type" : "object",
@@ -77,7 +86,8 @@
         "id" : { "type" : "string" },
         "val" : { "type" : "number" },
         "count" : { "type" : "number" }
-      }
+      },
+      "additionalProperties" : false
     },
     "MyGame_Example_Monster" : {
       "type" : "object",
@@ -119,7 +129,8 @@
         "vector_of_doubles" : { "type" : "array", "items" : { "type" : "number" } },
         "parent_namespace_test" : { "$ref" : "#/definitions/MyGame_InParentNamespace" }
       },
-      "required" : [ "name"]
+      "required" : ["name"],
+      "additionalProperties" : false
     },
     "MyGame_Example_TypeAliases" : {
       "type" : "object",
@@ -136,7 +147,8 @@
         "f64" : { "type" : "number" },
         "v8" : { "type" : "array", "items" : { "type" : "number" } },
         "vf64" : { "type" : "array", "items" : { "type" : "number" } }
-      }
+      },
+      "additionalProperties" : false
     }
   },
   "$ref" : "#/definitions/MyGame_Example_Monster"