diff --git a/var/spack/repos/builtin/packages/gtkplus/package.py b/var/spack/repos/builtin/packages/gtkplus/package.py
index 8c768a51c95..270b628efa7 100644
--- a/var/spack/repos/builtin/packages/gtkplus/package.py
+++ b/var/spack/repos/builtin/packages/gtkplus/package.py
@@ -114,7 +114,7 @@ def configure_args(self):
 
     @when('@:3.20.10')
     def meson(self, spec, prefix):
-        configure(*self.configure_args)
+        configure(*self.configure_args())
 
     @when('@:3.20.10')
     def build(self, spec, prefix):