A constant-depth circuit consists of AND and OR gates of unbounded fan-in, arranged in a constant number of layers, that read the input literals; for example, a depth-three circuit is an OR of CNFs or an AND of DNFs. The classical lower bound of Håstad (1989) states that every depth-$d$ circuit computing the parity function has $2^{\Omega(n^{1/(d-1)})}$ gates. This parity barrier stood for decades: no explicit function was known to require depth-$d$ circuits of size $2^{\omega(n^{1/(d-1)})}$ for any constant $d$. OpenAI (2026) recently announced that they broke this barrier for depth-three circuits: they gave an explicit function in P that requires OR-AND-OR circuits of size $2^{\omega(\sqrt{n})}$.
In this paper, we break the parity barrier at every constant depth with a simpler function. We prove that for every fixed $d \ge 3$, every depth-$d$ circuit computing the trilinear function $\sum_{i,j} a_{i+j} x_i y_j \bmod 2$ for $x,y \in \{0,1\}^n$ and $a \in \{0,1\}^{2n-1}$, requires $2^{\Omega((n\log n/\log\log n)^{1/(d-1)})}$ gates. Our proof combines the restriction lemma of OpenAI, for which we give a short new proof, with Håstad's switching lemma and the sparsification lemma of Calabro, Impagliazzo, and Paturi (2006).