diff --git a/src/keypair.c b/src/keypair.c
index 7c2c25b..5b72911 100644
--- a/src/keypair.c
+++ b/src/keypair.c
@@ -50,7 +50,7 @@ bool ntru_create_keypair(
 		goto cleanup;
 	}
 
-	if (!poly_inverse_poly_q(f, Fp, ctx)) {
+	if (!poly_inverse_poly_p(f, Fp, ctx)) {
 		retval = false;
 		goto cleanup;
 	}