diff --git a/docs/setup.md b/docs/setup.md
index e0da06569..664a20cd8 100644
--- a/docs/setup.md
+++ b/docs/setup.md
@@ -75,6 +75,25 @@ If you are using Gradle, add this to your dependencies:
 compile 'com.google.http-client:google-http-client:[VERSION]'
 ```
 
+## ProGuard
+
+The library uses reflection to access generic types and fields annotated with `@Key`. Add the
+following rules to your ProGuard configuration:
+
+```
+-keepattributes Signature,RuntimeVisibleAnnotations,AnnotationDefault
+
+-keepclassmembers class * {
+  @com.google.api.client.util.Key <fields>;
+}
+```
+
+When using `google-http-client-android`, also add:
+
+```
+-dontwarn com.google.api.client.extensions.android.**
+```
+
 ## Download the library with dependencies
 
 Download the latest assembly zip file from Maven Central and extract it on your computer. This zip
@@ -85,4 +104,3 @@ the dependencies folder. For more details about the contents of the download, se
 
 
 
-