diff --git a/ycmd/tests/cs/debug_info_test.py b/ycmd/tests/cs/debug_info_test.py
index 8f6258ffbd..ceb3364a05 100644
--- a/ycmd/tests/cs/debug_info_test.py
+++ b/ycmd/tests/cs/debug_info_test.py
@@ -17,12 +17,19 @@
 
 from hamcrest import ( assert_that, contains_exactly, empty, equal_to,
                        has_entries, has_entry, instance_of )
+
+from subprocess import Popen as _mockable_popen
+
 from unittest.mock import patch
 from unittest import TestCase
 
+from ycmd.completers.cs.cs_completer import PATH_TO_OMNISHARP_ROSLYN_BINARY
 from ycmd.completers.cs.hook import GetCompleter
 from ycmd.tests.cs import setUpModule, tearDownModule # noqa
-from ycmd.tests.cs import PathToTestFile, SharedYcmd
+from ycmd.tests.cs import ( PathToTestFile,
+                            SharedYcmd,
+                            IsolatedYcmd,
+                            WrapOmniSharpServer )
 from ycmd.tests.test_utils import ( BuildRequest,
                                     WaitUntilCompleterServerReady )
 from ycmd import user_options_store
@@ -197,14 +204,22 @@ def test_GetCompleter_RoslynNotFound( *args ):
     assert_that( not GetCompleter( user_options_store.GetAll() ) )
 
 
-  @patch( 'ycmd.completers.cs.cs_completer.FindExecutableWithFallback',
-          wraps = lambda x, fb: x if x == 'roslyn' else fb )
+  def _RoslynFromUserOption_popen_mock(*args, **kwargs):
+    assert_that( args[0][1], equal_to( 'my_roslyn.exe' ) )
+    args[0][1] = PATH_TO_OMNISHARP_ROSLYN_BINARY
+    return _mockable_popen(*args, **kwargs)
+
   @patch( 'os.path.isfile', return_value = True )
-  def test_GetCompleter_RoslynFromUserOption( *args ):
-    user_options = user_options_store.GetAll().copy(
-        roslyn_binary_path = 'roslyn' )
-    assert_that( GetCompleter( user_options )._roslyn_path,
-                 equal_to( 'roslyn' ) )
+  @patch( 'subprocess.Popen', wraps = _RoslynFromUserOption_popen_mock )
+  @IsolatedYcmd( { 'roslyn_binary_path': 'my_roslyn.exe' } )
+  def test_GetCompleter_RoslynFromUserOption( self, app, *args ):
+    filepath = PathToTestFile( 'testy', 'Program.cs' )
+    contents = ReadFile( filepath )
+    import subprocess
+    with WrapOmniSharpServer( app, filepath ):
+      request = BuildRequest( filepath = filepath, filetype = 'cs' )
+      response = app.post_json( '/debug_info', request )
+      subprocess.Popen.assert_called()
 
 
   @patch( 'os.path.isfile', return_value = False )