diff --git a/android/build.gradle b/android/build.gradle
index 1a1f559fca..234a852fca 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -8,7 +8,19 @@ android {
 		optimized {
 			storeFile file("debug.keystore")
 		}
-		release {
+
+		// Set these in a system global (or project local, but not checked in) gradle.properties .
+		if (project.hasProperty("RELEASE_STORE_FILE")) {
+			release {
+				storeFile file(RELEASE_STORE_FILE)
+				storePassword RELEASE_STORE_PASSWORD
+				keyAlias RELEASE_KEY_ALIAS
+				keyPassword RELEASE_KEY_PASSWORD
+			}
+		} else {
+			release {
+				// Can't build release builds without a key store.
+			}
 		}
 	}
 	compileSdkVersion 25