diff --git a/vm/src/stdlib/sys.rs b/vm/src/stdlib/sys.rs
index fa6480c92..9c0e59bf7 100644
--- a/vm/src/stdlib/sys.rs
+++ b/vm/src/stdlib/sys.rs
@@ -655,6 +655,7 @@ settrace() -- set the global debug tracing function
     let base_prefix = option_env!("RUSTPYTHON_BASEPREFIX").unwrap_or(prefix);
     let exec_prefix = option_env!("RUSTPYTHON_EXECPREFIX").unwrap_or(prefix);
     let base_exec_prefix = option_env!("RUSTPYTHON_BASEEXECPREFIX").unwrap_or(exec_prefix);
+    let platlibdir = option_env!("RUSTPYTHON_PLATLIBDIR").unwrap_or("lib");
 
     extend_module!(vm, module, {
       "__name__" => ctx.new_ascii_literal(ascii!("sys")),
@@ -702,6 +703,7 @@ settrace() -- set the global debug tracing function
       "base_prefix" => ctx.new_utf8_str(base_prefix),
       "exec_prefix" => ctx.new_utf8_str(exec_prefix),
       "base_exec_prefix" => ctx.new_utf8_str(base_exec_prefix),
+      "platlibdir" => ctx.new_utf8_str(platlibdir),
       "exit" => named_function!(ctx, sys, exit),
       "abiflags" => ctx.new_utf8_str(ABIFLAGS.to_owned()),
       "audit" => named_function!(ctx, sys, audit),