diff --git a/bottleneck/src/bn_config.py b/bottleneck/src/bn_config.py
index 43264c5a6..b3f1f7de4 100644
--- a/bottleneck/src/bn_config.py
+++ b/bottleneck/src/bn_config.py
@@ -3,6 +3,7 @@
 """
 import os
 import sys
+import platform
 import textwrap
 from distutils.command.config import config as Config
 from typing import List
@@ -11,7 +12,9 @@
     ("HAVE_ATTRIBUTE_OPTIMIZE_OPT_3", '__attribute__((optimize("O3")))')
 ]
 
-OPTIONAL_HEADERS = [("HAVE_SSE2", "emmintrin.h")]
+OPTIONAL_HEADERS = (
+    [] if platform.machine() == "arm64" else [("HAVE_SSE2", "emmintrin.h")]
+)
 
 OPTIONAL_INTRINSICS = [
     ("HAVE___BUILTIN_ISNAN", "__builtin_isnan", "0."),
diff --git a/bottleneck/src/reduce_template.c b/bottleneck/src/reduce_template.c
index f80d96ab0..6ef249ae9 100644
--- a/bottleneck/src/reduce_template.c
+++ b/bottleneck/src/reduce_template.c
@@ -1313,7 +1313,7 @@ REDUCE_ONE(anynan, DTYPE0) {
 #else
                 for (npy_intp i = 0; (i < loop_count) && (f == 0); i++) {
                     for (npy_intp j = 0; j < LOOP_SIZE; j++) {
-                        ai = pa[vector_offset + i * LOOP_SIZE + j];
+                        const npy_DTYPE0 ai = pa[vector_offset + i * LOOP_SIZE + j];
                         f += bn_isnan(ai);
                     }
                 }
@@ -1517,7 +1517,7 @@ REDUCE_ONE(allnan, DTYPE0) {
 #else
                 for (npy_intp i = 0; (i < loop_count) && (f == 0); i++) {
                     for (npy_intp j = 0; j < LOOP_SIZE; j++) {
-                        ai = pa[vector_offset + i * LOOP_SIZE + j];
+                        const npy_DTYPE0 ai = pa[vector_offset + i * LOOP_SIZE + j];
                         f += !bn_isnan(ai);
                     }
                 }