diff --git a/pebble_tool/sdk/requirements.py b/pebble_tool/sdk/requirements.py
index 2df8002..53a0528 100644
--- a/pebble_tool/sdk/requirements.py
+++ b/pebble_tool/sdk/requirements.py
@@ -54,7 +54,7 @@ def _qemu_version(self):
         if 'qemu' not in self._version_cache:
             qemu_path = os.environ.get('PEBBLE_QEMU_PATH', 'qemu-pebble')
             try:
-                result = subprocess.check_output([qemu_path, '--version'])
+                result = subprocess.check_output([qemu_path, '--version'], stderr=subprocess.STDOUT)
             except (subprocess.CalledProcessError, OSError):
                 version = None
             else:
@@ -70,7 +70,7 @@ def _pypkjs_version(self):
         if 'pypkjs' not in self._version_cache:
             pypkjs_path = os.environ.get('PHONESIM_PATH', 'phonesim.py')
             try:
-                result = subprocess.check_output([sys.executable, pypkjs_path, '--version'])
+                result = subprocess.check_output([sys.executable, pypkjs_path, '--version'], stderr=subprocess.STDOUT)
             except subprocess.CalledProcessError:
                 version = '1.0.4'  # The version before we started including version numbers.
             except OSError: