diff --git a/FEBioFluid/FEFluidSolutesSolver.h b/FEBioFluid/FEFluidSolutesSolver.h
index 6fce3ee96..910ad8673 100644
--- a/FEBioFluid/FEFluidSolutesSolver.h
+++ b/FEBioFluid/FEFluidSolutesSolver.h
@@ -64,6 +64,9 @@ class FEBIOFLUID_API FEFluidSolutesSolver : public FENewtonSolver
     
     //! Initialize linear equation system
     bool InitEquations() override;
+
+	//! preferred matrix type should be unsymmetric.
+	Matrix_Type PreferredMatrixType() const override { return REAL_UNSYMMETRIC; };
     
 public:
     //{ --- evaluation and update ---
diff --git a/FEBioFluid/FEFluidSolver.h b/FEBioFluid/FEFluidSolver.h
index f65cf60fc..3b7f42b1a 100644
--- a/FEBioFluid/FEFluidSolver.h
+++ b/FEBioFluid/FEFluidSolver.h
@@ -59,6 +59,9 @@ class FEBIOFLUID_API FEFluidSolver : public FENewtonSolver
     //! Initialize linear equation system
     bool InitEquations() override;
 	bool InitEquations2() override;
+
+	//! preferred matrix type should be unsymmetric.
+	Matrix_Type PreferredMatrixType() const override { return REAL_UNSYMMETRIC; };
     
 public:
     //{ --- evaluation and update ---
diff --git a/FEBioFluid/FEMultiphasicFSISolver.h b/FEBioFluid/FEMultiphasicFSISolver.h
index c42988e51..ed1e3c9dc 100644
--- a/FEBioFluid/FEMultiphasicFSISolver.h
+++ b/FEBioFluid/FEMultiphasicFSISolver.h
@@ -62,6 +62,9 @@ class FEBIOFLUID_API FEMultiphasicFSISolver : public FENewtonSolver
     //! Generate warnings if needed
     void SolverWarnings();
     
+	//! preferred matrix type should be unsymmetric.
+	Matrix_Type PreferredMatrixType() const override { return REAL_UNSYMMETRIC; };
+
 public:
     //{ --- evaluation and update ---
     //! Perform an update
diff --git a/FEBioFluid/FEPolarFluidSolver.h b/FEBioFluid/FEPolarFluidSolver.h
index 8dcd1e8e2..cc3886c20 100644
--- a/FEBioFluid/FEPolarFluidSolver.h
+++ b/FEBioFluid/FEPolarFluidSolver.h
@@ -65,6 +65,9 @@ class FEBIOFLUID_API FEPolarFluidSolver : public FENewtonSolver
     //! Generate warnings if needed
     void SolverWarnings();
     
+	//! preferred matrix type should be unsymmetric.
+	Matrix_Type PreferredMatrixType() const override { return REAL_UNSYMMETRIC; };
+
 public:
     //{ --- evaluation and update ---
     //! Perform an update
diff --git a/FEBioFluid/FESolutesSolver.h b/FEBioFluid/FESolutesSolver.h
index 94060498c..a6ec16d59 100644
--- a/FEBioFluid/FESolutesSolver.h
+++ b/FEBioFluid/FESolutesSolver.h
@@ -46,6 +46,9 @@ class FESolutesSolver : public FENewtonSolver
     bool InitEquations() override;
 	bool InitEquations2() override;
 
+	//! preferred matrix type should be unsymmetric.
+	Matrix_Type PreferredMatrixType() const override { return REAL_UNSYMMETRIC; };
+
 public:
     //{ --- evaluation and update ---
     //! Perform an update
diff --git a/FEBioFluid/FEThermoFluidSolver.h b/FEBioFluid/FEThermoFluidSolver.h
index 11f23915b..554119160 100644
--- a/FEBioFluid/FEThermoFluidSolver.h
+++ b/FEBioFluid/FEThermoFluidSolver.h
@@ -65,6 +65,9 @@ class FEBIOFLUID_API FEThermoFluidSolver : public FENewtonSolver
     bool InitEquations() override;
     bool InitEquations2() override;
 
+	//! preferred matrix type should be unsymmetric.
+	Matrix_Type PreferredMatrixType() const override { return REAL_UNSYMMETRIC; };
+
 public:
     //{ --- evaluation and update ---
     //! Perform an update
diff --git a/FEBioMix/FEMultiphasicSolver.h b/FEBioMix/FEMultiphasicSolver.h
index 430790a2a..bfcda663a 100644
--- a/FEBioMix/FEMultiphasicSolver.h
+++ b/FEBioMix/FEMultiphasicSolver.h
@@ -60,6 +60,9 @@ class FEBIOMIX_API FEMultiphasicSolver : public FENewtonSolver
 	//! Generate warnings if needed
 	void SolverWarnings();
 
+	//! preferred matrix type should be unsymmetric.
+	Matrix_Type PreferredMatrixType() const override { return REAL_UNSYMMETRIC; };
+
 public:
 	void Update(vector<double>& ui) override;