diff --git a/apex/builder.go b/apex/builder.go
index 1a1f22b..432fcaa 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -618,6 +618,8 @@
 
 			implicitInputs = append(implicitInputs, androidManifestFile)
 			optFlags = append(optFlags, "--android_manifest "+androidManifestFile.String())
+		} else if a.testApex {
+			optFlags = append(optFlags, "--test_only")
 		}
 
 		// Determine target/min sdk version from the context