diff --git a/include/TFEL/Math/Matrix/TMatrixTMatrixExpr.hxx b/include/TFEL/Math/Matrix/TMatrixTMatrixExpr.hxx
index 8aa6a420c..1da9560c9 100644
--- a/include/TFEL/Math/Matrix/TMatrixTMatrixExpr.hxx
+++ b/include/TFEL/Math/Matrix/TMatrixTMatrixExpr.hxx
@@ -36,11 +36,9 @@ namespace tfel::math {
   template <unsigned short N,
             unsigned short M,
             unsigned short K,
-            typename A,
-            typename B>
+            MatrixConcept A,
+            MatrixConcept B>
   struct TMatrixTMatrixExpr : public ExprBase {
-    static_assert(implementsMatrixConcept<A>());
-    static_assert(implementsMatrixConcept<B>());
 
     using RunTimeProperties = EmptyRunTimeProperties;
     using Result = BinaryOperationResult<A, B, OpMult>;
diff --git a/include/TFEL/Math/Matrix/TMatrixTVectorExpr.hxx b/include/TFEL/Math/Matrix/TMatrixTVectorExpr.hxx
index b33bcbf86..e32c8ae92 100644
--- a/include/TFEL/Math/Matrix/TMatrixTVectorExpr.hxx
+++ b/include/TFEL/Math/Matrix/TMatrixTVectorExpr.hxx
@@ -37,11 +37,8 @@ namespace tfel::math {
    * \tparam A : type of the tiny matrix object (can be a reference)
    * \tparam B : type of the tiny vector object (can be a reference)
    */
-  template <unsigned short N, unsigned short M, typename A, typename B>
+  template <unsigned short N, unsigned short M, MatrixConcept A, MatrixConcept B>
   struct TMatrixTVectorExpr : public ExprBase {
-    static_assert(implementsMatrixConcept<A>());
-    static_assert(implementsVectorConcept<B>());
-
     //! a simple alias
     typedef EmptyRunTimeProperties RunTimeProperties;
     //! \brief return the runtime properties
diff --git a/include/TFEL/Math/Matrix/TVectorTMatrixExpr.hxx b/include/TFEL/Math/Matrix/TVectorTMatrixExpr.hxx
index 6ba10cf09..615829996 100644
--- a/include/TFEL/Math/Matrix/TVectorTMatrixExpr.hxx
+++ b/include/TFEL/Math/Matrix/TVectorTMatrixExpr.hxx
@@ -29,10 +29,8 @@
 
 namespace tfel::math {
 
-  template <unsigned short N, unsigned short M, typename A, typename B>
+  template <unsigned short N, unsigned short M, VectorConcept A, MatrixConcept B>
   struct TVectorTMatrixExpr : public ExprBase {
-    static_assert(implementsVectorConcept<A>());
-    static_assert(implementsMatrixConcept<B>());
 
     using RunTimeProperties = EmptyRunTimeProperties;
     using Result = BinaryOperationResult<A, B, OpMult>;