diff --git a/os/BUILD b/os/BUILD
index c392a4a..16df5d3 100644
--- a/os/BUILD
+++ b/os/BUILD
@@ -38,6 +38,12 @@
     constraint_setting = ":os",
 )
 
+# For platforms with no OS, like microcontrollers.
+constraint_value(
+    name = "none",
+    constraint_setting = ":os",
+)
+
 ### Apple OS Values
 
 constraint_value(
@@ -51,6 +57,11 @@
     constraint_setting = ":os",
 )
 
+alias(
+    name = "macos",
+    actual = ":osx",
+)
+
 constraint_value(
     name = "tvos",
     constraint_setting = ":os",
@@ -60,3 +71,8 @@
     name = "watchos",
     constraint_setting = ":os",
 )
+
+constraint_value(
+    name = "qnx",
+    constraint_setting = ":os",
+)