diff --git a/BUILD.bazel b/BUILD.bazel
index 5b644fee..0b47b5da 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -1,6 +1,8 @@
 load("@rules_cc//cc:defs.bzl", "cc_library")
 load("//tools/project:build_defs.bzl", "project")
 
+package(features = ["layering_check"])
+
 project()
 
 genrule(
diff --git a/auto_tests/BUILD.bazel b/auto_tests/BUILD.bazel
index c7a40c8c..0fa6cd9b 100644
--- a/auto_tests/BUILD.bazel
+++ b/auto_tests/BUILD.bazel
@@ -1,5 +1,7 @@
 load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
 
+package(features = ["layering_check"])
+
 cc_library(
     name = "check_compat",
     testonly = True,
@@ -36,6 +38,20 @@ flaky_tests = {
         "//c-toxcore/toxav",
         "//c-toxcore/toxcore",
         "//c-toxcore/toxcore:DHT_srcs",
+        "//c-toxcore/toxcore:Messenger",
+        "//c-toxcore/toxcore:TCP_connection",
+        "//c-toxcore/toxcore:ccompat",
+        "//c-toxcore/toxcore:crypto_core",
+        "//c-toxcore/toxcore:friend_connection",
+        "//c-toxcore/toxcore:logger",
+        "//c-toxcore/toxcore:mono_time",
+        "//c-toxcore/toxcore:net_crypto",
+        "//c-toxcore/toxcore:network",
+        "//c-toxcore/toxcore:onion",
+        "//c-toxcore/toxcore:onion_announce",
+        "//c-toxcore/toxcore:onion_client",
         "//c-toxcore/toxencryptsave",
+        "@libsodium",
+        "@libvpx",
     ],
 ) for src in glob(["*_test.c"])]
diff --git a/other/BUILD.bazel b/other/BUILD.bazel
index 63652181..ebfde238 100644
--- a/other/BUILD.bazel
+++ b/other/BUILD.bazel
@@ -1,6 +1,8 @@
 load("@rules_cc//cc:defs.bzl", "cc_binary")
 load("//tools:no_undefined.bzl", "cc_library")
 
+package(features = ["layering_check"])
+
 cc_library(
     name = "bootstrap_node_packets",
     srcs = ["bootstrap_node_packets.c"],
@@ -15,5 +17,11 @@ cc_binary(
     deps = [
         "//c-toxcore/testing:misc_tools",
         "//c-toxcore/toxcore",
+        "//c-toxcore/toxcore:DHT",
+        "//c-toxcore/toxcore:TCP_connection",
+        "//c-toxcore/toxcore:friend_requests",
+        "//c-toxcore/toxcore:logger",
+        "//c-toxcore/toxcore:mono_time",
+        "//c-toxcore/toxcore:network",
     ],
 )
diff --git a/other/fun/BUILD.bazel b/other/fun/BUILD.bazel
index 7ed252a4..19809393 100644
--- a/other/fun/BUILD.bazel
+++ b/other/fun/BUILD.bazel
@@ -1,5 +1,7 @@
 load("@rules_cc//cc:defs.bzl", "cc_binary")
 
+package(features = ["layering_check"])
+
 #cc_binary(
 #    name = "cracker",
 #    srcs = ["cracker.c"],
@@ -16,6 +18,7 @@ cc_binary(
     srcs = ["cracker_simple.c"],
     deps = [
         "//c-toxcore/testing:misc_tools",
+        "//c-toxcore/toxcore:ccompat",
         "@libsodium",
     ],
 )
@@ -24,6 +27,7 @@ cc_binary(
     name = "minimal-save-generator",
     srcs = ["minimal-save-generator.c"],
     deps = [
+        "//c-toxcore/toxcore:ccompat",
         "@libsodium",
     ],
 )
@@ -34,6 +38,7 @@ cc_binary(
     copts = ["-w"],
     deps = [
         "//c-toxcore/testing:misc_tools",
+        "//c-toxcore/toxcore:ccompat",
         "@libsodium",
     ],
 )
@@ -53,5 +58,6 @@ cc_binary(
     deps = [
         "//c-toxcore/testing:misc_tools",
         "//c-toxcore/toxcore",
+        "//c-toxcore/toxcore:ccompat",
     ],
 )
diff --git a/super_donators/BUILD.bazel b/super_donators/BUILD.bazel
index f268d5d5..353e34af 100644
--- a/super_donators/BUILD.bazel
+++ b/super_donators/BUILD.bazel
@@ -1,5 +1,7 @@
 load("@rules_cc//cc:defs.bzl", "cc_binary")
 
+package(features = ["layering_check"])
+
 cc_binary(
     name = "grencez_tok5",
     srcs = ["grencez_tok5.c"],
diff --git a/toxcore/BUILD.bazel b/toxcore/BUILD.bazel
index 862f8eee..e11f91fc 100644
--- a/toxcore/BUILD.bazel
+++ b/toxcore/BUILD.bazel
@@ -66,6 +66,8 @@ cc_library(
     srcs = ["logger.c"],
     hdrs = ["logger.h"],
     visibility = [
+        "//c-toxcore/auto_tests:__pkg__",
+        "//c-toxcore/other:__pkg__",
         "//c-toxcore/other/bootstrap_daemon:__pkg__",
         "//c-toxcore/toxav:__pkg__",
     ],
@@ -84,6 +86,8 @@ cc_library(
     srcs = ["mono_time.c"],
     hdrs = ["mono_time.h"],
     visibility = [
+        "//c-toxcore/auto_tests:__pkg__",
+        "//c-toxcore/other:__pkg__",
         "//c-toxcore/other/bootstrap_daemon:__pkg__",
         "//c-toxcore/testing:__pkg__",
         "//c-toxcore/toxav:__pkg__",
@@ -116,6 +120,7 @@ cc_library(
         "util.h",
     ],
     visibility = [
+        "//c-toxcore/auto_tests:__pkg__",
         "//c-toxcore/other:__pkg__",
         "//c-toxcore/other/bootstrap_daemon:__pkg__",
         "//c-toxcore/toxav:__pkg__",
@@ -190,6 +195,7 @@ cc_library(
         "ping.h",
     ],
     visibility = [
+        "//c-toxcore/other:__pkg__",
         "//c-toxcore/other/bootstrap_daemon:__pkg__",
         "//c-toxcore/testing:__pkg__",
     ],
@@ -227,6 +233,7 @@ cc_library(
     ],
     visibility = [
         "//c-toxcore/auto_tests:__pkg__",
+        "//c-toxcore/other:__pkg__",
         "//c-toxcore/other/bootstrap_daemon:__pkg__",
     ],
     deps = [
@@ -242,6 +249,7 @@ cc_library(
     name = "onion",
     srcs = ["onion.c"],
     hdrs = ["onion.h"],
+    visibility = ["//c-toxcore/auto_tests:__pkg__"],
     deps = [
         ":DHT",
         ":crypto_core",
@@ -266,7 +274,11 @@ cc_library(
         "//tools/config:linux": ["-DTCP_SERVER_USE_EPOLL=1"],
         "//conditions:default": [],
     }),
-    visibility = ["//c-toxcore/other/bootstrap_daemon:__pkg__"],
+    visibility = [
+        "//c-toxcore/auto_tests:__pkg__",
+        "//c-toxcore/other:__pkg__",
+        "//c-toxcore/other/bootstrap_daemon:__pkg__",
+    ],
     deps = [
         ":crypto_core",
         ":list",
@@ -291,6 +303,7 @@ cc_library(
     name = "net_crypto",
     srcs = ["net_crypto.c"],
     hdrs = ["net_crypto.h"],
+    visibility = ["//c-toxcore/auto_tests:__pkg__"],
     deps = [
         ":DHT",
         ":TCP_connection",
@@ -303,7 +316,10 @@ cc_library(
     name = "onion_announce",
     srcs = ["onion_announce.c"],
     hdrs = ["onion_announce.h"],
-    visibility = ["//c-toxcore/other/bootstrap_daemon:__pkg__"],
+    visibility = [
+        "//c-toxcore/auto_tests:__pkg__",
+        "//c-toxcore/other/bootstrap_daemon:__pkg__",
+    ],
     deps = [
         ":DHT",
         ":mono_time",
@@ -316,6 +332,7 @@ cc_library(
     name = "onion_client",
     srcs = ["onion_client.c"],
     hdrs = ["onion_client.h"],
+    visibility = ["//c-toxcore/auto_tests:__pkg__"],
     deps = [
         ":DHT",
         ":mono_time",
@@ -329,6 +346,7 @@ cc_library(
     name = "friend_connection",
     srcs = ["friend_connection.c"],
     hdrs = ["friend_connection.h"],
+    visibility = ["//c-toxcore/auto_tests:__pkg__"],
     deps = [
         ":DHT",
         ":mono_time",
@@ -353,7 +371,11 @@ cc_library(
     name = "friend_requests",
     srcs = ["friend_requests.c"],
     hdrs = ["friend_requests.h"],
-    visibility = ["//c-toxcore/testing:__pkg__"],
+    visibility = [
+        "//c-toxcore/auto_tests:__pkg__",
+        "//c-toxcore/other:__pkg__",
+        "//c-toxcore/testing:__pkg__",
+    ],
     deps = [
         ":friend_connection",
         ":network",
@@ -365,6 +387,7 @@ cc_library(
     srcs = ["Messenger.c"],
     hdrs = ["Messenger.h"],
     visibility = [
+        "//c-toxcore/auto_tests:__pkg__",
         "//c-toxcore/testing:__pkg__",
         "//c-toxcore/toxav:__pkg__",
     ],
diff --git a/toxencryptsave/BUILD.bazel b/toxencryptsave/BUILD.bazel
index 395c4a20..1b083c5f 100644
--- a/toxencryptsave/BUILD.bazel
+++ b/toxencryptsave/BUILD.bazel
@@ -1,5 +1,7 @@
 load("//tools:no_undefined.bzl", "cc_library")
 
+package(features = ["layering_check"])
+
 filegroup(
     name = "public_headers",
     srcs = ["toxencryptsave.h"],
@@ -21,6 +23,7 @@ cc_library(
         ":defines",
         "//c-toxcore/toxcore:ccompat",
         "//c-toxcore/toxcore:crypto_core",
+        "@libsodium",
     ],
 )
 
@@ -31,7 +34,11 @@ cc_library(
         "*.h",
     ]),
     visibility = ["//c-toxcore/other:__pkg__"],
-    deps = ["//c-toxcore/toxcore:crypto_core"],
+    deps = [
+        "//c-toxcore/toxcore:ccompat",
+        "//c-toxcore/toxcore:crypto_core",
+        "@libsodium",
+    ],
 )
 
 CIMPLE_SRCS = glob(