diff --git a/cuda_bindings_13/pyproject.toml b/cuda_bindings_13/pyproject.toml
index 59ebdf93f78..471fa0ee45c 100644
--- a/cuda_bindings_13/pyproject.toml
+++ b/cuda_bindings_13/pyproject.toml
@@ -1,6 +1,7 @@
 # SPDX-FileCopyrightText: Copyright (c) 2023-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 [build-system]
+# Keep the external tools in sync with dependency-groups.build.
 requires = [
     "setuptools>=80.0.0",
     "setuptools_scm[simple]>=8,!=10.1",
@@ -42,6 +43,12 @@ all = [
 ]
 
 [dependency-groups]
+# Keep build in sync with build-system.requires; install local cuda-pathfinder separately.
+build = [
+    "setuptools>=80.0.0",
+    "setuptools_scm[simple]>=8,!=10.1",
+    "cython>=3.2.5,<3.3",
+]
 test = [
     "cython>=3.2.5,<3.3",
     "setuptools>=80.0.0",
diff --git a/cuda_core/pyproject.toml b/cuda_core/pyproject.toml
index e850dadacfe..160c437a25a 100644
--- a/cuda_core/pyproject.toml
+++ b/cuda_core/pyproject.toml
@@ -3,6 +3,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 [build-system]
+# Keep the external tools in sync with dependency-groups.build.
 requires = [
     "setuptools>=80",
     "setuptools-scm[simple]>=8,!=10.1",
@@ -62,6 +63,12 @@ cu12 = ["cuda-bindings[all]>=12.9.8,<13", "cuda-toolkit==12.*"]
 cu13 = ["cuda-bindings[all]>=13.4.1,<14", "cuda-toolkit==13.*"]
 
 [dependency-groups]
+# Keep build in sync with build-system.requires; install local cuda-pathfinder separately.
+build = [
+    "setuptools>=80",
+    "setuptools-scm[simple]>=8,!=10.1",
+    "Cython>=3.2.5,<3.3",
+]
 test = [
     "cython>=3.2.5,<3.3",
     "setuptools>=80",
diff --git a/cuda_pathfinder/pyproject.toml b/cuda_pathfinder/pyproject.toml
index 00a6f60bb1f..904463b7022 100644
--- a/cuda_pathfinder/pyproject.toml
+++ b/cuda_pathfinder/pyproject.toml
@@ -11,6 +11,12 @@ dynamic = ["version", "readme"]
 dependencies = []
 
 [dependency-groups]
+# Keep build in sync with build-system.requires.
+build = [
+    "setuptools>=80.0.0",
+    "setuptools_scm[simple]>=8,!=10.1",
+    "wheel",
+]
 test = [
     "pytest==9.1.0",
     "pytest-mock==3.15.1",
@@ -93,6 +99,7 @@ packages = { find = { include = ["cuda*"] } }
 readme = { file = ["DESCRIPTION.rst"], content-type = "text/x-rst" }
 
 [build-system]
+# Keep requires in sync with dependency-groups.build.
 requires = [
     "setuptools>=80.0.0",
     "setuptools_scm[simple]>=8,!=10.1",