diff --git a/requirements.txt b/requirements.txt
index 87821677e3..6e1dfa1ba5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -26,6 +26,9 @@ freetype-py==2.5.1
 jinja2==3.1.6
 bleak==3.0.2
 smpclient==7.3.0
+# smp 4.2+ needs cbor2 6+, which ships no Intel macOS wheels (arm64 only).
+smp==4.2.0; platform_system != "Darwin" or platform_machine != "x86_64"
+smp==4.1.0; platform_system == "Darwin" and platform_machine == "x86_64"
 requests==2.34.2
 py7zr==1.1.3
 platformdirs==4.12.3  # native esp-idf toolchain global cache dir