diff --git a/deepblast/nw.py b/deepblast/nw.py
index 2af8c0d..0f6136c 100644
--- a/deepblast/nw.py
+++ b/deepblast/nw.py
@@ -55,7 +55,7 @@ def _forward_pass_numba(theta, A):
         for j in range(1, M + 1):
             maxargs[x] = A[i - 1, j - 1] + V[i - 1, j]  # x
             maxargs[m] = V[i - 1, j - 1]  # m
-            maxargs[y] = A[i - j, 1 - 1] + V[i, j - 1]  # y
+            maxargs[y] = A[i - 1, j - 1] + V[i, j - 1]  # y
             v, Q[i, j] = _soft_max_numba(maxargs)
             V[i, j] = theta[i - 1, j - 1] + v
     Vt = V[N, M]
diff --git a/deepblast/sw.py b/deepblast/sw.py
index 35ad239..f15e578 100644
--- a/deepblast/sw.py
+++ b/deepblast/sw.py
@@ -55,7 +55,7 @@ def _forward_pass_numba(theta, A):
         for j in range(2, M + 1):
             maxargs[x] = A[i - 1, j - 1] + V[i - 1, j]  # x
             maxargs[m] = V[i - 1, j - 1]  # m
-            maxargs[y] = A[i - j, 1 - 1] + V[i, j - 1]  # y
+            maxargs[y] = A[i - 1, j - 1] + V[i, j - 1]  # y
             v, Q[i, j] = _soft_max_numba(maxargs)
             V[i, j] = theta[i - 1, j - 1] + v
     Vt = V[N, M]