diff --git a/MathLib/LinAlg/Lis/LisMatrix.cpp b/MathLib/LinAlg/Lis/LisMatrix.cpp
index a6e2a8a8d2270b549789e544ee1efb2326db8011..5d7788ab09b9bbfb35068f8541e99b6a3daa2a11 100644
--- a/MathLib/LinAlg/Lis/LisMatrix.cpp
+++ b/MathLib/LinAlg/Lis/LisMatrix.cpp
@@ -15,7 +15,9 @@
 #include "LisMatrix.h"
 
 #include <cmath>
-#include <cassert>
+#include <cstdlib>
+
+#include <logog/include/logog.hpp>
 
 #include "LisVector.h"
 #include "LisCheck.h"
@@ -79,7 +81,11 @@ int LisMatrix::add(std::size_t rowId, std::size_t colId, double v)
 
 void LisMatrix::write(const std::string &filename) const
 {
-    assert(_is_assembled);
+    if (!_is_assembled)
+    {
+        ERR("LisMatrix::write(): matrix not assembled.");
+        std::abort();
+    }
     lis_output_matrix(_AA, LIS_FMT_MM, const_cast<char*>(filename.c_str()));
 }
 
@@ -103,7 +109,11 @@ double LisMatrix::getMaxDiagCoeff()
 
 void LisMatrix::multiply(const LisVector &x, LisVector &y) const
 {
-    assert(_is_assembled);
+    if (!_is_assembled)
+    {
+        ERR("LisMatrix::multiply(): matrix not assembled.");
+        std::abort();
+    }
     int ierr = lis_matvec(_AA, const_cast<LisVector*>(&x)->getRawVector(), y.getRawVector());
     checkLisError(ierr);
 }