diff --git a/gni/snapshot_toolchain.gni b/gni/snapshot_toolchain.gni
index cce97f7f17..99de816372 100644
--- a/gni/snapshot_toolchain.gni
+++ b/gni/snapshot_toolchain.gni
@@ -65,15 +65,21 @@ if (v8_snapshot_toolchain == "") {
     # therefore snapshots will need to be built using native mksnapshot
     # in combination with qemu
     v8_snapshot_toolchain = current_toolchain
+  } else if (host_cpu == current_cpu) {
+    # Cross-build from same ISA on one OS to another. For example:
+    # * targeting win/x64 on a linux/x64 host
+    # * targeting win/arm64 on a mac/arm64 host
+    v8_snapshot_toolchain = host_toolchain
   } else if (host_cpu == "arm64" && current_cpu == "x64") {
     # Cross-build from arm64 to intel (likely on an Apple Silicon mac).
     v8_snapshot_toolchain =
         "//build/toolchain/${host_os}:clang_arm64_v8_$v8_current_cpu"
   } else if (host_cpu == "x64") {
     # This is a cross-compile from an x64 host to either a non-Intel target
-    # cpu or a different target OS.
+    # cpu or to 32-bit x86 on a different target OS.
 
-    if (v8_current_cpu == "x64" || v8_current_cpu == "x86") {
+    assert(v8_current_cpu != "x64", "handled by host_cpu == current_cpu branch")
+    if (v8_current_cpu == "x86") {
       _cpus = v8_current_cpu
     } else if (v8_current_cpu == "arm64" || v8_current_cpu == "mips64el" ||
                v8_current_cpu == "riscv64" || v8_current_cpu == "loong64") {