diff --git a/src/compiletest/procsrv.rs b/src/compiletest/procsrv.rs
index 0afbd95d644..ab96b5eced7 100644
--- a/src/compiletest/procsrv.rs
+++ b/src/compiletest/procsrv.rs
@@ -9,9 +9,13 @@ fn target_env(lib_path: str, prog: str) -> [(str,str)] {
 
     let mut env = os::env();
 
+    // Make sure we include the aux directory in the path
+    assert prog.ends_with(".exe");
+    let aux_path = prog.slice(0u, prog.len() - 4u) + ".libaux";
+
     env = vec::map(env) {|pair|
         let (k,v) = pair;
-        if k == "PATH" { ("PATH", v + ";" + lib_path) }
+        if k == "PATH" { ("PATH", v + ";" + lib_path + ";" + aux_path) }
         else { (k,v) }
     };
     if str::ends_with(prog, "rustc.exe") {