diff --git a/Bembel/src/util/Constants.hpp b/Bembel/src/util/Constants.hpp
index cca136afe..343ad3c60 100644
--- a/Bembel/src/util/Constants.hpp
+++ b/Bembel/src/util/Constants.hpp
@@ -1,4 +1,4 @@
-// This file is part of Bembel, the higher order C++ boundary element library.
+// This file is part of Bembel, the higher order C++ boundary element library.
 //
 // Copyright (C) 2022 see <http://www.bembel.eu>
 //
@@ -11,6 +11,10 @@
 #ifndef BEMBEL_SRC_UTIL_CONSTANTS_HPP_
 #define BEMBEL_SRC_UTIL_CONSTANTS_HPP_
 
+#ifndef M_PI
+// since M_PI is not defined in Windows MSVC++ 
+#define M_PI 3.14159265358979323846
+#endif
 namespace Bembel {
 namespace Constants {
 
diff --git a/examples/HelmholtzAdjointDoubleLayerH2.cpp b/examples/HelmholtzAdjointDoubleLayerH2.cpp
index bc843e708..3d3e78d3a 100644
--- a/examples/HelmholtzAdjointDoubleLayerH2.cpp
+++ b/examples/HelmholtzAdjointDoubleLayerH2.cpp
@@ -1,4 +1,4 @@
-// This file is part of Bembel, the higher order C++ boundary element library.
+// This file is part of Bembel, the higher order C++ boundary element library.
 //
 // Copyright (C) 2024 see <http://www.bembel.eu>
 //
@@ -94,7 +94,7 @@ int main() {
       auto system_matrix = -0.5 * M + AK;  // important: do NOT change auto!
 
       // solve system
-      GMRES<typeof(system_matrix), IdentityPreconditioner> gmres;
+      GMRES<decltype(system_matrix), IdentityPreconditioner> gmres;
       gmres.compute(system_matrix);
       VectorXcd rho = gmres.solve(disc_lf.get_discrete_linear_form());
 
diff --git a/examples/HelmholtzDoubleLayerH2.cpp b/examples/HelmholtzDoubleLayerH2.cpp
index b382d0211..21e181961 100644
--- a/examples/HelmholtzDoubleLayerH2.cpp
+++ b/examples/HelmholtzDoubleLayerH2.cpp
@@ -1,4 +1,4 @@
-// This file is part of Bembel, the higher order C++ boundary element library.
+// This file is part of Bembel, the higher order C++ boundary element library.
 //
 // Copyright (C) 2024 see <http://www.bembel.eu>
 //
@@ -90,7 +90,7 @@ int main() {
       auto system_matrix = 0.5 * M + K;  // important: do NOT change auto!
 
       // solve system
-      GMRES<typeof(system_matrix), IdentityPreconditioner> gmres;
+      GMRES<decltype(system_matrix), IdentityPreconditioner> gmres;
       gmres.compute(system_matrix);
       VectorXcd rho = gmres.solve(disc_lf.get_discrete_linear_form());
 
diff --git a/examples/LaplaceAdjointDoubleLayerH2.cpp b/examples/LaplaceAdjointDoubleLayerH2.cpp
index 512c2f49a..10d834cec 100644
--- a/examples/LaplaceAdjointDoubleLayerH2.cpp
+++ b/examples/LaplaceAdjointDoubleLayerH2.cpp
@@ -1,4 +1,4 @@
-// This file is part of Bembel, the higher order C++ boundary element library.
+// This file is part of Bembel, the higher order C++ boundary element library.
 //
 // Copyright (C) 2024 see <http://www.bembel.eu>
 //
@@ -90,7 +90,7 @@ int main() {
       auto system_matrix = 0.5 * M + AK;  // important: do NOT change auto!
 
       // solve system
-      GMRES<typeof(system_matrix), IdentityPreconditioner> gmres;
+      GMRES<decltype(system_matrix), IdentityPreconditioner> gmres;
       gmres.compute(system_matrix);
       VectorXd rho = gmres.solve(disc_lf.get_discrete_linear_form());
 
diff --git a/examples/LaplaceDoubleLayerH2.cpp b/examples/LaplaceDoubleLayerH2.cpp
index 08a1889a6..0ab8b01fd 100644
--- a/examples/LaplaceDoubleLayerH2.cpp
+++ b/examples/LaplaceDoubleLayerH2.cpp
@@ -1,4 +1,4 @@
-// This file is part of Bembel, the higher order C++ boundary element library.
+// This file is part of Bembel, the higher order C++ boundary element library.
 //
 // Copyright (C) 2024 see <http://www.bembel.eu>
 //
@@ -87,7 +87,7 @@ int main() {
       auto system_matrix = -0.5 * M + K;  // important: do NOT change auto!
 
       // solve system
-      GMRES<typeof(system_matrix), IdentityPreconditioner> gmres;
+      GMRES<decltype(system_matrix), IdentityPreconditioner> gmres;
       gmres.compute(system_matrix);
       VectorXd rho = gmres.solve(disc_lf.get_discrete_linear_form());