1 files changed, 2 insertions, 2 deletions
diff --git a/mesonbuild/mesonmain.py b/mesonbuild/mesonmain.py
index dd265c41b..ca7a18414 100644
--- a/mesonbuild/mesonmain.py
+++ b/mesonbuild/mesonmain.py
@@ -240,14 +240,14 @@ def validate_original_args(args):
 
     def has_startswith(coll, target):
         for entry in coll:
-            if entry.startswith(target):
+            if entry.startswith(target + '=') or entry == target:
                 return True
         return False
     #ds = [x for x in args if x.startswith('-D')]
     #longs = [x for x in args if x.startswith('--')]
     for optionkey in itertools.chain(mesonbuild.options.BUILTIN_DIR_OPTIONS, mesonbuild.options.BUILTIN_CORE_OPTIONS):
         longarg = mesonbuild.options.argparse_name_to_arg(optionkey.name)
-        shortarg = f'-D{optionkey.name}='
+        shortarg = f'-D{optionkey.name}'
         if has_startswith(args, longarg) and has_startswith(args, shortarg):
             sys.exit(
                 f'Got argument {optionkey.name} as both {shortarg} and {longarg}. Pick one.')