diff --git a/Makefile.in b/Makefile.in
index a760155bbd9..153092d26f6 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -97,7 +97,7 @@
 #     make check-stage1-rpass TESTNAME=my-shiny-new-test
 #
 #     // Having trouble figuring out which test is failing? Turn off parallel tests
-#     make check-stage1-std RUST_TEST_TASKS=1
+#     make check-stage1-std RUST_TEST_THREADS=1
 #
 # This is hardly all there is to know of The Rust Build System's
 # mysteries. The tale continues on the wiki[1].
diff --git a/src/compiletest/compiletest.rs b/src/compiletest/compiletest.rs
index 7fbe772b7f5..01c4e99b77c 100644
--- a/src/compiletest/compiletest.rs
+++ b/src/compiletest/compiletest.rs
@@ -224,7 +224,7 @@ pub fn run_tests(config: &Config) {
         // android debug-info test uses remote debugger
         // so, we test 1 task at once.
         // also trying to isolate problems with adb_run_wrapper.sh ilooping
-        env::set_var("RUST_TEST_TASKS","1");
+        env::set_var("RUST_TEST_THREADS","1");
     }
 
     match config.mode {
@@ -232,7 +232,7 @@ pub fn run_tests(config: &Config) {
             // Some older versions of LLDB seem to have problems with multiple
             // instances running in parallel, so only run one test task at a
             // time.
-            env::set_var("RUST_TEST_TASKS", "1");
+            env::set_var("RUST_TEST_THREADS", "1");
         }
         _ => { /* proceed */ }
     }
diff --git a/src/compiletest/header.rs b/src/compiletest/header.rs
index 21cebc61b3a..6899fa13974 100644
--- a/src/compiletest/header.rs
+++ b/src/compiletest/header.rs
@@ -131,7 +131,7 @@ pub fn load_props(testfile: &Path) -> TestProps {
         true
     });
 
-    for key in vec!["RUST_TEST_NOCAPTURE", "RUST_TEST_TASKS"] {
+    for key in vec!["RUST_TEST_NOCAPTURE", "RUST_TEST_THREADS"] {
         match env::var(key) {
             Ok(val) =>
                 if exec_env.iter().find(|&&(ref x, _)| *x == key.to_string()).is_none() {
diff --git a/src/libtest/lib.rs b/src/libtest/lib.rs
index 02ddeea46bf..e4ccd49e807 100644
--- a/src/libtest/lib.rs
+++ b/src/libtest/lib.rs
@@ -338,7 +338,7 @@ The FILTER regex is tested against the name of all tests to run, and
 only those tests that match are run.
 
 By default, all tests are run in parallel. This can be altered with the
-RUST_TEST_TASKS environment variable when running tests (set it to 1).
+RUST_TEST_THRADS environment variable when running tests (set it to 1).
 
 All tests have their standard output and standard error captured by default.
 This can be overridden with the --nocapture flag or the RUST_TEST_NOCAPTURE=1
@@ -843,12 +843,12 @@ fn run_tests<F>(opts: &TestOpts,
 
 fn get_concurrency() -> uint {
     use std::rt;
-    match env::var("RUST_TEST_TASKS") {
+    match env::var("RUST_TEST_THREADS") {
         Ok(s) => {
             let opt_n: Option<uint> = s.parse().ok();
             match opt_n {
                 Some(n) if n > 0 => n,
-                _ => panic!("RUST_TEST_TASKS is `{}`, should be a positive integer.", s)
+                _ => panic!("RUST_TEST_THREADS is `{}`, should be a positive integer.", s)
             }
         }
         Err(..) => {
diff --git a/src/test/run-fail/test-tasks-invalid-value.rs b/src/test/run-fail/test-tasks-invalid-value.rs
index 8c9cd2d63cb..94ed641c79c 100644
--- a/src/test/run-fail/test-tasks-invalid-value.rs
+++ b/src/test/run-fail/test-tasks-invalid-value.rs
@@ -8,12 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// This checks that RUST_TEST_TASKS not being 1, 2, ... is detected
+// This checks that RUST_TEST_THREADS not being 1, 2, ... is detected
 // properly.
 
 // error-pattern:should be a positive integer
 // compile-flags: --test
-// exec-env:RUST_TEST_TASKS=foo
+// exec-env:RUST_TEST_THREADS=foo
 // ignore-pretty: does not work well with `--test`
 
 #[test]
diff --git a/src/test/run-pass/tcp-connect-timeouts.rs b/src/test/run-pass/tcp-connect-timeouts.rs
index d1a3edcfbc5..5462a996f73 100644
--- a/src/test/run-pass/tcp-connect-timeouts.rs
+++ b/src/test/run-pass/tcp-connect-timeouts.rs
@@ -10,7 +10,7 @@
 
 // ignore-pretty
 // compile-flags:--test
-// exec-env:RUST_TEST_TASKS=1
+// exec-env:RUST_TEST_THREADS=1
 
 // Tests for the connect_timeout() function on a TcpStream. This runs with only
 // one test task to ensure that errors are timeouts, not file descriptor