diff --git a/pw_build/BUILD.gn b/pw_build/BUILD.gn
index bb83617..02105cf 100644
--- a/pw_build/BUILD.gn
+++ b/pw_build/BUILD.gn
@@ -141,14 +141,6 @@
 group("empty") {
 }
 
-pool("pip_pool") {
-  depth = 1
-}
-
-pool("copy_from_cipd_pool") {
-  depth = 1
-}
-
 # Requirements for the pw_python_package lint targets.
 pw_python_requirements("python_lint") {
   requirements = [
@@ -164,8 +156,3 @@
     "python.rst",
   ]
 }
-
-# Pool to limit a single thread to download external Go packages at a time.
-pool("go_download_pool") {
-  depth = 1
-}
diff --git a/pw_build/copy_from_cipd.gni b/pw_build/copy_from_cipd.gni
index 19d332a..aff8afa 100644
--- a/pw_build/copy_from_cipd.gni
+++ b/pw_build/copy_from_cipd.gni
@@ -69,7 +69,7 @@
 
     # Parallel calls might both be invoking CIPD on the same directory which
     # might work but is redundant, so serialize calls.
-    pool = "$dir_pw_build:copy_from_cipd_pool"
+    pool = "$dir_pw_build/pool:copy_from_cipd($default_toolchain)"
 
     # TODO(pwbug/335): This should somehow track the actual .a for changes as
     # well.
diff --git a/pw_build/go.gni b/pw_build/go.gni
index eadb93b..d13af2e 100644
--- a/pw_build/go.gni
+++ b/pw_build/go.gni
@@ -140,7 +140,7 @@
     skip_empty_args = true
 
     # Limit download parallelization to 1.
-    pool = "$dir_pw_build:go_download_pool"
+    pool = "$dir_pw_build/pool:go_download($default_toolchain)"
   }
 
   # Run a "go build" command with the environment configured from metadata.
diff --git a/pw_build/pool/BUILD.gn b/pw_build/pool/BUILD.gn
new file mode 100644
index 0000000..1102744
--- /dev/null
+++ b/pw_build/pool/BUILD.gn
@@ -0,0 +1,30 @@
+# Copyright 2021 The Pigweed Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+
+# Pools are used to limit concurrency; we don't want multiple instances.
+assert(current_toolchain == default_toolchain)
+
+# Pool to serialize python package installs.
+pool("pip") {
+  depth = 1
+}
+
+pool("copy_from_cipd") {
+  depth = 1
+}
+
+# Pool to limit a single thread to download external Go packages at a time.
+pool("go_download") {
+  depth = 1
+}
diff --git a/pw_build/python.gni b/pw_build/python.gni
index 217a7f8..fdd5b78 100644
--- a/pw_build/python.gni
+++ b/pw_build/python.gni
@@ -410,7 +410,7 @@
         stamp = true
 
         # Parallel pip installations don't work, so serialize pip invocations.
-        pool = "$dir_pw_build:pip_pool"
+        pool = "$dir_pw_build/pool:pip($default_toolchain)"
 
         foreach(dep, _python_deps) {
           # We need to add a suffix to the target name, but the label is
@@ -727,7 +727,7 @@
       ]
     }
 
-    pool = "$dir_pw_build:pip_pool"
+    pool = "$dir_pw_build/pool:pip($default_toolchain)"
     stamp = true
   }
 
diff --git a/pw_tokenizer/database.gni b/pw_tokenizer/database.gni
index 2508470..07d441f 100644
--- a/pw_tokenizer/database.gni
+++ b/pw_tokenizer/database.gni
@@ -91,15 +91,12 @@
     not_needed([ "_domain" ])
   }
 
-  # Restrict parallelism for updating this database file to one thread. This
-  # makes it safe to update it from multiple toolchains.
-  pool("$target_name._pool") {
-    depth = 1
-  }
-
   pw_python_action(target_name) {
     script = "$dir_pw_tokenizer/py/pw_tokenizer/database.py"
-    pool = ":$target_name._pool"
+
+    # Restrict parallelism for updating this database file to one thread. This
+    # makes it safe to update it from multiple toolchains.
+    pool = "$dir_pw_tokenizer/pool:database($default_toolchain)"
 
     inputs = _input_databases
 
diff --git a/pw_tokenizer/pool/BUILD.gn b/pw_tokenizer/pool/BUILD.gn
new file mode 100644
index 0000000..cdb5bc3
--- /dev/null
+++ b/pw_tokenizer/pool/BUILD.gn
@@ -0,0 +1,20 @@
+# Copyright 2021 The Pigweed Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+
+# Pools are used to limit concurrency; we don't want multiple instances.
+assert(current_toolchain == default_toolchain)
+
+pool("database") {
+  depth = 1
+}