diff --git a/sklearn/tree/_classes.py b/sklearn/tree/_classes.py
index 2ce58759d8253..dc08bee65d3d9 100644
--- a/sklearn/tree/_classes.py
+++ b/sklearn/tree/_classes.py
@@ -401,7 +401,7 @@ def _fit(
         max_leaf_nodes = -1 if self.max_leaf_nodes is None else self.max_leaf_nodes
 
         if sample_weight is not None:
-            sample_weight = _check_sample_weight(sample_weight, X, DOUBLE)
+            sample_weight = _check_sample_weight(sample_weight, X, dtype=DOUBLE)
 
         if y is not None and expanded_class_weight is not None:
             if sample_weight is not None:
diff --git a/sklearn/utils/_cython_blas.pyx b/sklearn/utils/_cython_blas.pyx
index c242e59e1b9de..ac23d0c4000ff 100644
--- a/sklearn/utils/_cython_blas.pyx
+++ b/sklearn/utils/_cython_blas.pyx
@@ -126,8 +126,8 @@ cdef void _gemv(BLAS_Order order, BLAS_Trans ta, int m, int n, floating alpha,
                 floating beta, floating *y, int incy) noexcept nogil:
     """y := alpha * op(A).x + beta * y"""
     cdef char ta_ = ta
-    if order == RowMajor:
-        ta_ = NoTrans if ta == Trans else Trans
+    if order == BLAS_Order.RowMajor:
+        ta_ = BLAS_Trans.NoTrans if ta == BLAS_Trans.Trans else BLAS_Trans.Trans
         if floating is float:
             sgemv(&ta_, &n, &m, &alpha, <float *> A, &lda, <float *> x,
                   &incx, &beta, y, &incy)
@@ -148,8 +148,10 @@ cpdef _gemv_memview(BLAS_Trans ta, floating alpha, const floating[:, :] A,
     cdef:
         int m = A.shape[0]
         int n = A.shape[1]
-        BLAS_Order order = ColMajor if A.strides[0] == A.itemsize else RowMajor
-        int lda = m if order == ColMajor else n
+        BLAS_Order order = (
+            BLAS_Order.ColMajor if A.strides[0] == A.itemsize else BLAS_Order.RowMajor
+        )
+        int lda = m if order == BLAS_Order.ColMajor else n
 
     _gemv(order, ta, m, n, alpha, &A[0, 0], lda, &x[0], 1, beta, &y[0], 1)
 
@@ -158,7 +160,7 @@ cdef void _ger(BLAS_Order order, int m, int n, floating alpha,
                const floating *x, int incx, const floating *y,
                int incy, floating *A, int lda) noexcept nogil:
     """A := alpha * x.y.T + A"""
-    if order == RowMajor:
+    if order == BLAS_Order.RowMajor:
         if floating is float:
             sger(&n, &m, &alpha, <float *> y, &incy, <float *> x, &incx, A, &lda)
         else:
@@ -175,8 +177,10 @@ cpdef _ger_memview(floating alpha, const floating[::1] x,
     cdef:
         int m = A.shape[0]
         int n = A.shape[1]
-        BLAS_Order order = ColMajor if A.strides[0] == A.itemsize else RowMajor
-        int lda = m if order == ColMajor else n
+        BLAS_Order order = (
+            BLAS_Order.ColMajor if A.strides[0] == A.itemsize else BLAS_Order.RowMajor
+        )
+        int lda = m if order == BLAS_Order.ColMajor else n
 
     _ger(order, m, n, alpha, &x[0], 1, &y[0], 1, &A[0, 0], lda)
 
@@ -194,7 +198,7 @@ cdef void _gemm(BLAS_Order order, BLAS_Trans ta, BLAS_Trans tb, int m, int n,
     cdef:
         char ta_ = ta
         char tb_ = tb
-    if order == RowMajor:
+    if order == BLAS_Order.RowMajor:
         if floating is float:
             sgemm(&tb_, &ta_, &n, &m, &k, &alpha, <float*>B,
                   &ldb, <float*>A, &lda, &beta, C, &ldc)
@@ -214,19 +218,21 @@ cpdef _gemm_memview(BLAS_Trans ta, BLAS_Trans tb, floating alpha,
                     const floating[:, :] A, const floating[:, :] B, floating beta,
                     floating[:, :] C):
     cdef:
-        int m = A.shape[0] if ta == NoTrans else A.shape[1]
-        int n = B.shape[1] if tb == NoTrans else B.shape[0]
-        int k = A.shape[1] if ta == NoTrans else A.shape[0]
+        int m = A.shape[0] if ta == BLAS_Trans.NoTrans else A.shape[1]
+        int n = B.shape[1] if tb == BLAS_Trans.NoTrans else B.shape[0]
+        int k = A.shape[1] if ta == BLAS_Trans.NoTrans else A.shape[0]
         int lda, ldb, ldc
-        BLAS_Order order = ColMajor if A.strides[0] == A.itemsize else RowMajor
+        BLAS_Order order = (
+            BLAS_Order.ColMajor if A.strides[0] == A.itemsize else BLAS_Order.RowMajor
+        )
 
-    if order == RowMajor:
-        lda = k if ta == NoTrans else m
-        ldb = n if tb == NoTrans else k
+    if order == BLAS_Order.RowMajor:
+        lda = k if ta == BLAS_Trans.NoTrans else m
+        ldb = n if tb == BLAS_Trans.NoTrans else k
         ldc = n
     else:
-        lda = m if ta == NoTrans else k
-        ldb = k if tb == NoTrans else n
+        lda = m if ta == BLAS_Trans.NoTrans else k
+        ldb = k if tb == BLAS_Trans.NoTrans else n
         ldc = m
 
     _gemm(order, ta, tb, m, n, k, alpha, &A[0, 0],