diff --git a/adelie/matrix.py b/adelie/matrix.py
index 9dce6280..7b9379ee 100644
--- a/adelie/matrix.py
+++ b/adelie/matrix.py
@@ -624,13 +624,13 @@ def interaction(
             pairs_seen.add((key, val))
     if len(pairs) <= 0:
         raise ValueError("No valid pairs exist. There must be at least one valid pair.")
-    pairs = np.array(pairs, dtype=np.int32)
+    pairs = np.array(pairs, dtype=int)
 
     class _interaction(core_base, py_base):
         def __init__(self):
             self._mat = np.array(mat, copy=copy)
             self._pairs = pairs
-            self._levels = np.array(levels, copy=True, dtype=np.int32)
+            self._levels = np.array(levels, copy=True, dtype=int)
             core_base.__init__(self, self._mat, self._pairs, self._levels, n_threads)
             py_base.__init__(self, n_threads=n_threads)
         
@@ -822,7 +822,7 @@ def one_hot(
     class _one_hot(core_base, py_base):
         def __init__(self):
             self._mat = np.array(mat, copy=copy)
-            self._levels = np.array(levels, copy=True, dtype=np.int32)
+            self._levels = np.array(levels, copy=True, dtype=int)
             core_base.__init__(self, self._mat, self._levels, n_threads)
             py_base.__init__(self, n_threads=n_threads)
         
@@ -1318,7 +1318,7 @@ def subset(
     class _subset(core_base, py_base):
         def __init__(self):
             self._mat = mat
-            self._indices = np.array(indices, copy=True, dtype=np.int32)
+            self._indices = np.array(indices, copy=True, dtype=int)
             core_base.__init__(self, self._mat, self._indices, n_threads)
             py_base.__init__(self, n_threads=n_threads)
         
diff --git a/adelie/src/include/adelie_core/matrix/matrix_naive_base.hpp b/adelie/src/include/adelie_core/matrix/matrix_naive_base.hpp
index dd90dcd3..684af617 100644
--- a/adelie/src/include/adelie_core/matrix/matrix_naive_base.hpp
+++ b/adelie/src/include/adelie_core/matrix/matrix_naive_base.hpp
@@ -7,7 +7,7 @@
 namespace adelie_core {
 namespace matrix {
 
-template <class ValueType, class IndexType=int> 
+template <class ValueType, class IndexType=Eigen::Index> 
 class MatrixNaiveBase
 {
 protected:
diff --git a/adelie/src/include/adelie_core/matrix/matrix_naive_concatenate.hpp b/adelie/src/include/adelie_core/matrix/matrix_naive_concatenate.hpp
index 5d86801e..ee2ce635 100644
--- a/adelie/src/include/adelie_core/matrix/matrix_naive_concatenate.hpp
+++ b/adelie/src/include/adelie_core/matrix/matrix_naive_concatenate.hpp
@@ -144,7 +144,7 @@ class MatrixNaiveCConcatenate: public MatrixNaiveBase<ValueType>
             const auto slice = _slice_map[j_curr];
             auto& mat = *_mat_list[slice];
             const auto index = _index_map[j_curr];
-            const int q_curr = std::min(mat.cols()-index, q-n_processed);
+            const int q_curr = std::min<int>(mat.cols()-index, q-n_processed);
             mat.bmul(index, q_curr, v, weights, out.segment(n_processed, q_curr));
             n_processed += q_curr;
         }
@@ -163,7 +163,7 @@ class MatrixNaiveCConcatenate: public MatrixNaiveBase<ValueType>
             const auto slice = _slice_map[j_curr];
             auto& mat = *_mat_list[slice];
             const auto index = _index_map[j_curr];
-            const int q_curr = std::min(mat.cols()-index, q-n_processed);
+            const int q_curr = std::min<int>(mat.cols()-index, q-n_processed);
             mat.btmul(index, q_curr, v.segment(n_processed, q_curr), out);
             n_processed += q_curr;
         }