diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 07d494f0463..5c45ed9fca8 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -219,6 +219,8 @@ repos:
     rev: "35dbc940c2bd4499ebf39aba00ad717e05cec9b5"  # frozen: v0.22.0
     hooks:
       - id: cython-lint
+        # Cross-file rules need .pxd declarations and .pyx implementations in one process.
+        require_serial: true
         args: [--no-pycodestyle]
         exclude: ^cuda_bindings_(?:12|13)/
         additional_dependencies:
diff --git a/cuda_core/cuda/core/_stream.pyx b/cuda_core/cuda/core/_stream.pyx
index 1876885e0cf..066a680e2d9 100644
--- a/cuda_core/cuda/core/_stream.pyx
+++ b/cuda_core/cuda/core/_stream.pyx
@@ -517,7 +517,7 @@ cpdef Stream default_stream():
     else:
         return LEGACY_DEFAULT_STREAM
 
-cdef inline bint Stream_handle_is_default_token(cydriver.CUstream s) noexcept nogil:
+cdef bint Stream_handle_is_default_token(cydriver.CUstream s) noexcept nogil:
     """Return True for the raw CU_STREAM_LEGACY and CU_STREAM_PER_THREAD tokens.
 
     These tokens carry no context of their own; they refer to whatever context
@@ -527,12 +527,12 @@ cdef inline bint Stream_handle_is_default_token(cydriver.CUstream s) noexcept no
     return h == <uintptr_t>cydriver.CU_STREAM_LEGACY or h == <uintptr_t>cydriver.CU_STREAM_PER_THREAD
 
 
-cdef inline bint Stream_is_default_token(Stream self) noexcept nogil:
+cdef bint Stream_is_default_token(Stream self) noexcept nogil:
     """Return True when this stream is CU_STREAM_LEGACY or CU_STREAM_PER_THREAD."""
     return Stream_handle_is_default_token(as_cu(self._h_stream))
 
 
-cdef inline bint Stream_is_legacy_default_token(Stream self) noexcept nogil:
+cdef bint Stream_is_legacy_default_token(Stream self) noexcept nogil:
     """Return True only for CU_STREAM_LEGACY.
 
     Unlike CU_STREAM_PER_THREAD, the legacy default stream token is rejected
diff --git a/cuda_core/cuda/core/graph/_graph_node.pyx b/cuda_core/cuda/core/graph/_graph_node.pyx
index 09a52f09884..c028be968bd 100644
--- a/cuda_core/cuda/core/graph/_graph_node.pyx
+++ b/cuda_core/cuda/core/graph/_graph_node.pyx
@@ -923,7 +923,7 @@ cdef inline OpaqueHandle _buffer_attachment_owner(Buffer buf, str label):
     return attachment_owner
 
 
-cdef inline OpaqueHandle _resolve_memcpy_operand(
+cdef OpaqueHandle _resolve_memcpy_operand(
         object operand, object owner, str side,
         cydriver.CUdeviceptr* out_ptr) except *:
     """Resolve an operand to a pointer and optional attachment owner.