1 files changed, 1 insertions, 1 deletions
diff --git a/matrix.c b/matrix.c
index 8dc3fe5..ebcdecd 100644
--- a/matrix.c
+++ b/matrix.c
@@ -357,7 +357,7 @@ Vector *matrix_backsubst(const Matrix *R, const Vector *y)
 
     double sum;
 
-    for (int i = x->m; i >= 0; --i)
+    for (int i = x->m - 1; i >= 0; --i)
     {
         sum = vector_at(y, i);
         for (size_t j = i + 1; j < x->m; ++j)