diff --git a/test/core/run_tests.py b/test/core/run_tests.py
index 2e9674f94ba..3f35394daab 100644
--- a/test/core/run_tests.py
+++ b/test/core/run_tests.py
@@ -78,7 +78,7 @@ def construct_arg_dict(params_opts, cli_options):
 
         for arg in cli_options:
             if "=" in arg:
-                given_opt, val = arg.split("=")
+                given_opt, val = arg.split("=", 1)
                 has_value = True
             else:
                 given_opt = arg
@@ -96,9 +96,9 @@ def construct_arg_dict(params_opts, cli_options):
                     value = val
                 else:
                     if secondary_supplied:
-                        value = not each_param.default
+                        value = False
                     else:
-                        value = each_param.default
+                        value = True
 
                 if each_param.multiple:
                     if key not in result_dict: