diff --git a/modules/audio_processing/BUILD.gn b/modules/audio_processing/BUILD.gn
index 4b1b46db97..b03b40d255 100644
--- a/modules/audio_processing/BUILD.gn
+++ b/modules/audio_processing/BUILD.gn
@@ -273,6 +273,7 @@ rtc_source_set("audio_generator_interface") {
 
 rtc_source_set("audio_generator_factory") {
   visibility = [ "*" ]
+  testonly = true
   sources = [
     "include/audio_generator_factory.cc",
     "include/audio_generator_factory.h",