diff --git a/modules/openapi-generator-maven-plugin/README.md b/modules/openapi-generator-maven-plugin/README.md
index 65ddab54f94..7e423cf780c 100644
--- a/modules/openapi-generator-maven-plugin/README.md
+++ b/modules/openapi-generator-maven-plugin/README.md
@@ -138,6 +138,35 @@ Notice that some of these environment variable options may overwrite or conflict
The difference here is that you may define `generateModels` and `modelsToGenerate` as properties, while `globalProperties` may only be configured as a configuration node.
+### Type and import mappings
+
+To override the mappings between OpenAPI spec types and the types used in the generated code, set `typeMappings`.
+
+```xml
+
+
+
+ Double=java.math.BigDecimal
+
+
+```
+
+For types that are not already included in the generator configuration, you may need to add a corresponding `importMapping` too.
+
+```xml
+
+
+
+ binary=StreamingOutput
+ file=StreamingOutput
+
+
+ StreamingOutput=javax.ws.rs.core.StreamingOutput
+
+
+```
+
+
### Custom Generator
Specifying a custom generator is a bit different. It doesn't support the classpath:/ syntax, but it does support the fully qualified name of the package. You can also specify your custom templates, which also get pulled in. Notice the dependency on a project, in the plugin scope. That would be your generator/template jar.