Index: third_party/blake3/blake3.BUILD
--- third_party/blake3/blake3.BUILD.orig
+++ third_party/blake3/blake3.BUILD
@@ -39,6 +39,9 @@ cc_library(
         "@bazel_tools//src/conditions:linux_aarch64": [
             "c/blake3_neon.c",
         ],
+        "@bazel_tools//src/conditions:openbsd_aarch64": [
+            "c/blake3_neon.c",
+        ],
         "@bazel_tools//src/conditions:windows_x64": [
             "c/blake3_avx2_x86-64_windows_msvc.asm",
             "c/blake3_avx512_x86-64_windows_msvc.asm",
