diff --git a/build.py b/build.py
index 7d6eff5..480214d 100755
--- a/build.py
+++ b/build.py
@@ -216,7 +216,7 @@ def assemble(src, out):
 def compile(srcs, out, extra_flags = ''):
     if cc == 'cuik' and out.endswith('.o'):
         out = out[:-2]
-    flags = cc_flags_str + ' ' + extra_flags + ' '.join(args.cflags)
+    flags = cc_flags_str + ' ' + extra_flags + ' ' + ' '.join(args.cflags)
     inputs = ' '.join(map(quote, srcs))
     cmdline = f'{cc} {flags} {inputs} -o {quote(out)}'
     print('  $', cmdline)