diff --git a/llvm/utils/lit/lit/TestRunner.py b/llvm/utils/lit/lit/TestRunner.py
index a7e2705f609af..f88314547bb3f 100644
--- a/llvm/utils/lit/lit/TestRunner.py
+++ b/llvm/utils/lit/lit/TestRunner.py
@@ -92,12 +92,12 @@ class ShellEnvironment(object):
     we maintain a dir stack for pushd/popd.
     """
 
-    def __init__(self, cwd, env, umask=-1, ulimit={}):
+    def __init__(self, cwd, env, umask=-1, ulimit=None):
         self.cwd = cwd
         self.env = dict(env)
         self.umask = umask
         self.dirStack = []
-        self.ulimit = ulimit
+        self.ulimit = ulimit if ulimit else {}
 
     def change_dir(self, newdir):
         if os.path.isabs(newdir):
diff --git a/llvm/utils/lit/tests/Inputs/shtest-ulimit/ulimit_reset.txt b/llvm/utils/lit/tests/Inputs/shtest-ulimit/ulimit_reset.txt
new file mode 100644
index 0000000000000..011d6db6c127f
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-ulimit/ulimit_reset.txt
@@ -0,0 +1,3 @@
+# RUN: %{python} %S/print_limits.py
+# Fail the test so that we can assert on the output.
+# RUN: not echo return
diff --git a/llvm/utils/lit/tests/shtest-ulimit.py b/llvm/utils/lit/tests/shtest-ulimit.py
index e84327772d3a1..9a8febd3333c4 100644
--- a/llvm/utils/lit/tests/shtest-ulimit.py
+++ b/llvm/utils/lit/tests/shtest-ulimit.py
@@ -5,9 +5,9 @@
 # as well.
 # UNSUPPORTED: system-windows, system-solaris
 
-# RUN: not %{lit} -a -v %{inputs}/shtest-ulimit | FileCheck %s
+# RUN: not %{lit} -a -v %{inputs}/shtest-ulimit --order=lexical | FileCheck %s
 
-# CHECK: -- Testing: 2 tests{{.*}}
+# CHECK: -- Testing: 3 tests{{.*}}
 
 # CHECK-LABEL: FAIL: shtest-ulimit :: ulimit-bad-arg.txt ({{[^)]*}})
 # CHECK: ulimit -n
@@ -16,3 +16,6 @@
 # CHECK-LABEL: FAIL: shtest-ulimit :: ulimit_okay.txt ({{[^)]*}})
 # CHECK: ulimit -n 50
 # CHECK: RLIMIT_NOFILE=50
+
+# CHECK-LABEL: FAIL: shtest-ulimit :: ulimit_reset.txt ({{[^)]*}})
+# CHECK-NOT: RLIMIT_NOFILE=50