diff --git a/lib/truth/BUILD b/lib/truth/BUILD
index bb30945529..dc1d802a02 100644
--- a/lib/truth/BUILD
+++ b/lib/truth/BUILD
@@ -2,6 +2,7 @@ load("@rules_java//java:defs.bzl", "java_library")
 
 java_library(
     name = "truth",
+    testonly = True,
     data = ["//lib:LICENSE-DO_NOT_DISTRIBUTE"],
     visibility = ["//visibility:public"],
     exports = ["@truth//jar"],
@@ -14,6 +15,7 @@ java_library(
 
 java_library(
     name = "truth-java8-extension",
+    testonly = True,
     data = ["//lib:LICENSE-DO_NOT_DISTRIBUTE"],
     visibility = ["//visibility:public"],
     exports = ["@truth-java8-extension//jar"],
@@ -25,6 +27,7 @@ java_library(
 
 java_library(
     name = "truth-liteproto-extension",
+    testonly = True,
     data = ["//lib:LICENSE-DO_NOT_DISTRIBUTE"],
     visibility = ["//visibility:private"],
     exports = ["@truth-liteproto-extension//jar"],
@@ -37,6 +40,7 @@ java_library(
 
 java_library(
     name = "diffutils",
+    testonly = True,
     data = ["//lib:LICENSE-DO_NOT_DISTRIBUTE"],
     visibility = ["//visibility:private"],
     exports = ["@diffutils//jar"],
@@ -44,6 +48,7 @@ java_library(
 
 java_library(
     name = "truth-proto-extension",
+    testonly = True,
     data = ["//lib:LICENSE-DO_NOT_DISTRIBUTE"],
     visibility = ["//visibility:public"],
     exports = [