diff --git a/MODULE.bazel b/MODULE.bazel
index 2656e9bfd..af3664474 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -30,3 +30,11 @@ bazel_dep(name = "fuzztest", version = "20260219.0", dev_dependency = True, repo
 bazel_dep(name = "google_benchmark", version = "1.9.5", dev_dependency = True, repo_name = "com_github_google_benchmark")
 bazel_dep(name = "googletest", version = "1.17.0.bcr.2", dev_dependency = True, repo_name = "com_google_googletest")
 bazel_dep(name = "rules_fuzzing", version = "0.5.2", dev_dependency = True)
+
+# Note: Gloop is NOT a dev_dependency, but should never be used directly.  It is only included here
+# so that we can give visibility into TCMalloc internals.
+bazel_dep(
+    name = "gloop",
+    version = "20260708.rc1",
+    repo_name = "do_not_use_for_gloop_visibility_only",
+)
diff --git a/tcmalloc/BUILD b/tcmalloc/BUILD
index f245bf5e8..2061d68c6 100644
--- a/tcmalloc/BUILD
+++ b/tcmalloc/BUILD
@@ -48,7 +48,7 @@ cc_library(
     copts = TCMALLOC_DEFAULT_COPTS,
     visibility = [
         "//tcmalloc:__subpackages__",
-        "//tcmalloc:friends",
+        "@do_not_use_for_gloop_visibility_only//gloop:__subpackages__",
     ],
     deps = [
         ":malloc_extension",
@@ -1600,6 +1600,7 @@ cc_library(
     textual_hdrs = ["malloc_hook_invoke.h"],
     visibility = [
         ":__subpackages__",
+        "@do_not_use_for_gloop_visibility_only//gloop/base:__pkg__",
     ],
     deps = [
         "//tcmalloc/internal:config",
@@ -1632,9 +1633,3 @@ cc_library(
     ],
     alwayslink = 1,
 )
-
-# Expose internals to privileged external repositories.
-package_group(
-    name = "friends",
-    packages = [],
-)
diff --git a/tcmalloc/internal/BUILD b/tcmalloc/internal/BUILD
index 1114a9663..e37b45812 100644
--- a/tcmalloc/internal/BUILD
+++ b/tcmalloc/internal/BUILD
@@ -355,7 +355,7 @@ cc_library(
     hdrs = ["linux_syscall_support.h"],
     copts = TCMALLOC_DEFAULT_COPTS,
     visibility = [
-        "//tcmalloc:friends",
+        "@do_not_use_for_gloop_visibility_only//gloop/base:__subpackages__",
     ],
 )
 
@@ -1304,7 +1304,8 @@ cc_library(
     visibility = [
         "//tcmalloc:__pkg__",
         "//tcmalloc:__subpackages__",
-        "//tcmalloc:friends",
+        "@do_not_use_for_gloop_visibility_only//gloop/base:__subpackages__",
+        "@do_not_use_for_gloop_visibility_only//gloop/concurrent/rcu:__subpackages__",
     ],
     deps = [
         ":config",