Siman 485
Presented here for study, not as a practical ruling. The Shulchan Aruch rules by Sephardi custom, the Rema's glosses by Ashkenazi custom, and the Kitzur follows Ashkenazi custom. For a practical question, ask your rabbi.
א אָמַר: שְׁבוּעָה שֶׁלֹּא אֹכַל מַצָּה, סְתָם, אָסוּר לֶאֱכֹל מַצָּה בְּלֵיל פֶּסַח. אָמַר: שְׁבוּעָה שֶׁלֹּא אֹכַל מַצָּה בְּלֵיל פֶּסַח, לוֹקֶה וְאוֹכֵל מַצָּה בְּלֵיל פֶּסַח.
1 The Law Regarding One Who Swore Not to Eat Matzah (One Section): If a person swore generally, saying, "I swear not to eat matzah," he is forbidden to eat matzah on the night of Passover. However, if he specifically swore, "I swear not to eat matzah on the night of Passover," he receives lashes for taking an invalid oath and is still obligated to eat matzah on the night of Passover.