diff --git a/CMakeLists.txt b/CMakeLists.txt
index f763c5e..104eabe 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -32,7 +32,8 @@ add_custom_command(
 
 set(SPDLOG_ACTIVE_LEVEL "SPDLOG_LEVEL_OFF" CACHE STRING "Set the logging level (e.g. SPDLOG_LEVEL_DEBUG, or SPDLOG_LEVEL_OFF)")
 
-add_compile_options(-DSPDLOG_ACTIVE_LEVEL=${SPDLOG_ACTIVE_LEVEL})
+add_compile_options(-DSPDLOG_ACTIVE_LEVEL=${SPDLOG_ACTIVE_LEVEL} -DMODULE_API_EXPORTS)
+
 
 # Library
 
diff --git a/CMakeLists.txt.in b/CMakeLists.txt.in
index 46d3e61..5c472b3 100644
--- a/CMakeLists.txt.in
+++ b/CMakeLists.txt.in
@@ -28,7 +28,7 @@ ExternalProject_Add(Catch2
 )
 
 ExternalProject_Add(eigen
-    DOWNLOAD_COMMAND URL http://bitbucket.org/eigen/eigen/get/3.3.7.tar.bz2
+    DOWNLOAD_COMMAND URL https://gitlab.com/libeigen/eigen/-/archive/3.3.7/eigen-3.3.7.tar.bz2
     DOWNLOAD_DIR "${EXTERNAL_PROJECTS_DIR}"
     DOWNLOAD_NAME "eigen-3.3.7.tar.bz2"
     SOURCE_DIR "${EXTERNAL_PROJECTS_DIR}/eigen"
diff --git a/Readme.md b/Readme.md
index eeb5ecb..9071984 100644
--- a/Readme.md
+++ b/Readme.md
@@ -15,6 +15,7 @@ The corresponding code is in `src/matlab/example.m`.
 
 ## Build instructions
 Build requirements are a C++14 compiler, _cmake_ and _Python3_ for code generation.
+_Python3_ needs to have `sympy >= 1.10.1` installed.
 ```
 git clone git@github.com:RobMa/circle_fit.git
 cd circle_fit
diff --git a/src/c_interface.cpp b/src/c_interface.cpp
index 3e8fa2f..2cae115 100644
--- a/src/c_interface.cpp
+++ b/src/c_interface.cpp
@@ -6,9 +6,19 @@
 
 using namespace circle_fit;
 
+#ifdef _WIN32
+#  ifdef MODULE_API_EXPORTS
+#    define MODULE_API __declspec(dllexport)
+#  else
+#    define MODULE_API __declspec(dllimport)
+#  endif
+#else
+#  define MODULE_API
+#endif
+
 extern "C"
 {
-int estimate_circle_taubin(double x[], double y[], int length, double *out_x, double *out_y, double *out_r)
+MODULE_API int estimate_circle_taubin(double x[], double y[], int length, double *out_x, double *out_y, double *out_r)
 {
     if(length < 3 || x==nullptr || y == nullptr || out_x == nullptr || out_y == nullptr || out_r == nullptr) {
         SPDLOG_ERROR("Invalid arguments");
@@ -26,7 +36,7 @@ int estimate_circle_taubin(double x[], double y[], int length, double *out_x, do
     return true;
 }
 
-int estimate_circle_lm(double x[], double y[], int length, double rxy_init[3], double rxy_out[3])
+MODULE_API int estimate_circle_lm(double x[], double y[], int length, double rxy_init[3], double rxy_out[3])
 {
     if(length < 3 || x==nullptr || y == nullptr || rxy_init == nullptr || rxy_out == nullptr) {
         SPDLOG_ERROR("Invalid arguments");
@@ -46,7 +56,7 @@ int estimate_circle_lm(double x[], double y[], int length, double rxy_init[3], d
     return true;
 }
 
-int estimate_circle(double x[], double y[], int length, double *out_x, double *out_y, double *out_r)
+MODULE_API int estimate_circle(double x[], double y[], int length, double *out_x, double *out_y, double *out_r)
 {
     if(length < 3 || x==nullptr || y == nullptr || out_x == nullptr || out_y == nullptr || out_r == nullptr) {
         SPDLOG_ERROR("Invalid arguments");
@@ -61,7 +71,7 @@ int estimate_circle(double x[], double y[], int length, double *out_x, double *o
     return true;
 }
 
-int estimate_circle_lm_trace(double x[], double y[], int length, double rxy_init[3], int *out_numiters, double **out_x, double **out_y, double **out_r, double **out_grad_norm, double **out_mse)
+MODULE_API int estimate_circle_lm_trace(double x[], double y[], int length, double rxy_init[3], int *out_numiters, double **out_x, double **out_y, double **out_r, double **out_grad_norm, double **out_mse)
 {
     if(length < 3 || x==nullptr || y == nullptr || rxy_init == nullptr || out_numiters == nullptr || out_x == nullptr || out_y == nullptr || out_r == nullptr || out_grad_norm == nullptr || out_mse == nullptr) {
         SPDLOG_ERROR("Invalid arguments");
diff --git a/src/python/codegenerator.py b/src/python/codegenerator.py
index b0a798a..d7415fd 100644
--- a/src/python/codegenerator.py
+++ b/src/python/codegenerator.py
@@ -1,11 +1,11 @@
 #!/usr/bin/python3
 
 import sympy as sp
-from sympy.printing.codeprinter import Assignment
-from sympy.printing.cxxcode import CXX17CodePrinter
+from sympy.codegen.ast import Assignment
+from sympy.printing.cxx import CXX17CodePrinter
 
 class CxxMatrixPrinter(CXX17CodePrinter):
-    def _print_list(self, list_of_exprs):
+    def _print_List(self, list_of_exprs):
         if all(isinstance(x, sp.Eq) for x in list_of_exprs):
             list_of_lhs = [x.lhs for x in list_of_exprs]
             list_of_rhs = [x.rhs for x in list_of_exprs]
@@ -19,8 +19,8 @@ def _print_list(self, list_of_exprs):
                 lines.append(self._print(ass))
         return '\n'.join(lines)
 
-from sympy.printing.ccode import _as_macro_if_defined
-from sympy.printing.ccode import precedence
+from sympy.printing.c import _as_macro_if_defined
+from sympy.printing.c import precedence
 class EigenMatrixPrinter(CxxMatrixPrinter):
     def _print_MatrixElement(self, expr):
         return "{0}({1},{2})".format(
@@ -52,6 +52,7 @@ def _traverse_matrix_indices(self, mat):
 def codegen(expressions, template_path, output_path):
     p = EigenMatrixPrinter()
     p._print_Pow
+
     with open(template_path, 'r') as f:
         template = f.read()