diff --git a/linear_solver/cbc_interface.cc b/linear_solver/cbc_interface.cc
index f595dcdade..cc865e9089 100644
--- a/linear_solver/cbc_interface.cc
+++ b/linear_solver/cbc_interface.cc
@@ -163,6 +163,7 @@ class CBCInterface : public MPSolverInterface {
 
   virtual double ComputeExactConditionNumber() const {
     LOG(FATAL) << "Condition number only available for continuous problems";
+    return 0.0;
   }
 
  private:
diff --git a/linear_solver/clp_interface.cc b/linear_solver/clp_interface.cc
index df36195265..6cab8223a9 100644
--- a/linear_solver/clp_interface.cc
+++ b/linear_solver/clp_interface.cc
@@ -126,6 +126,7 @@ class CLPInterface : public MPSolverInterface {
   virtual double ComputeExactConditionNumber() const {
     // CLP does not provide the necessary API to access the inverse basis.
     LOG(FATAL) << "ComputeExactConditionNumber is not implemented in CLP.";
+    return 0.0;
   }
 
  private:
@@ -547,6 +548,7 @@ MPSolver::BasisStatus CLPInterface::TransformCLPBasisStatus(
       return MPSolver::FIXED_VALUE;
     default:
       LOG(FATAL) << "Unknown CLP basis status";
+      return MPSolver::FREE;
   }
 }
 
diff --git a/linear_solver/glpk_interface.cc b/linear_solver/glpk_interface.cc
index ef864f9f5e..c9bfa3d545 100644
--- a/linear_solver/glpk_interface.cc
+++ b/linear_solver/glpk_interface.cc
@@ -689,6 +689,7 @@ GLPKInterface::TransformGLPKBasisStatus(int glpk_basis_status) const {
       return MPSolver::FIXED_VALUE;
     default:
       LOG(FATAL) << "Unknown GLPK basis status";
+      return MPSolver::FREE;
   }
 }
 
diff --git a/linear_solver/scip_interface.cc b/linear_solver/scip_interface.cc
index 324654da85..757b44495b 100644
--- a/linear_solver/scip_interface.cc
+++ b/linear_solver/scip_interface.cc
@@ -98,10 +98,12 @@ class SCIPInterface : public MPSolverInterface {
   // Returns the basis status of a row.
   virtual MPSolver::BasisStatus row_status(int constraint_index) const {
     LOG(FATAL) << "Basis status only available for continuous problems";
+    return MPSolver::FREE;
   }
   // Returns the basis status of a column.
   virtual MPSolver::BasisStatus column_status(int variable_index) const {
     LOG(FATAL) << "Basis status only available for continuous problems";
+    return MPSolver::FREE;
   }
 
   // ----- Misc -----
@@ -129,6 +131,7 @@ class SCIPInterface : public MPSolverInterface {
 
   virtual double ComputeExactConditionNumber() const {
     LOG(FATAL) << "Condition number only available for continuous problems";
+    return 0.0;
   }
 
  private: