diff --git a/src/base/blas.rs b/src/base/blas.rs
index c19011fd..4d5a5b5d 100644
--- a/src/base/blas.rs
+++ b/src/base/blas.rs
@@ -9,10 +9,10 @@ use crate::base::constraint::{
 };
 use crate::base::dimension::{Const, Dim, Dynamic, U1, U2, U3, U4};
 use crate::base::storage::{Storage, StorageMut};
+use crate::base::uninit::Init;
 use crate::base::{
     DVectorSlice, DefaultAllocator, Matrix, Scalar, SquareMatrix, Vector, VectorSlice,
 };
-use crate::core::uninit::Init;
 
 /// # Dot/scalar product
 impl<T, R: Dim, C: Dim, S: RawStorage<T, R, C>> Matrix<T, R, C, S>
diff --git a/src/sparse/cs_matrix.rs b/src/sparse/cs_matrix.rs
index c717e90e..bb9f50a0 100644
--- a/src/sparse/cs_matrix.rs
+++ b/src/sparse/cs_matrix.rs
@@ -466,6 +466,7 @@ where
 {
     pub(crate) fn sort(&mut self)
     where
+        T: Zero,
         DefaultAllocator: Allocator<T, R>,
     {
         // Size = R
diff --git a/src/sparse/cs_matrix_ops.rs b/src/sparse/cs_matrix_ops.rs
index fba5d41b..419862a7 100644
--- a/src/sparse/cs_matrix_ops.rs
+++ b/src/sparse/cs_matrix_ops.rs
@@ -219,7 +219,7 @@ where
 impl<'a, 'b, T, R1, R2, C1, C2, S1, S2> Add<&'b CsMatrix<T, R2, C2, S2>>
     for &'a CsMatrix<T, R1, C1, S1>
 where
-    T: Scalar + ClosedAdd + ClosedMul + One,
+    T: Scalar + ClosedAdd + ClosedMul + Zero + One,
     R1: Dim,
     C1: Dim,
     R2: Dim,