diff --git a/poly2tri/common/dll_symbol.h b/poly2tri/common/dll_symbol.h
new file mode 100644
index 0000000..92c50cb
--- /dev/null
+++ b/poly2tri/common/dll_symbol.h
@@ -0,0 +1,56 @@
+/*
+ * Poly2Tri Copyright (c) 2009-2022, Poly2Tri Contributors
+ * https://github.com/jhasse/poly2tri
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ * * Neither the name of Poly2Tri nor the names of its contributors may be
+ *   used to endorse or promote products derived from this software without specific
+ *   prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef DLL_SYMBOL_H
+#define DLL_SYMBOL_H
+
+#if defined(_WIN32)
+#  define P2T_COMPILER_DLLEXPORT __declspec(dllexport)
+#  define P2T_COMPILER_DLLIMPORT __declspec(dllimport)
+#elif defined(__GNUC__)
+#  define P2T_COMPILER_DLLEXPORT __attribute__ ((visibility ("default")))
+#  define P2T_COMPILER_DLLIMPORT __attribute__ ((visibility ("default")))
+#else
+#  define P2T_COMPILER_DLLEXPORT
+#  define P2T_COMPILER_DLLIMPORT
+#endif
+
+#ifndef P2T_DLL_SYMBOL
+#  if defined(P2T_STATIC_EXPORTS)
+#    define P2T_DLL_SYMBOL
+#  elif defined(P2T_SHARED_EXPORTS)
+#    define P2T_DLL_SYMBOL P2T_COMPILER_DLLEXPORT
+#  else
+#    define P2T_DLL_SYMBOL P2T_COMPILER_DLLIMPORT
+#  endif
+#endif
+
+#endif
diff --git a/poly2tri/common/shapes.h b/poly2tri/common/shapes.h
index e150212..489558d 100644
--- a/poly2tri/common/shapes.h
+++ b/poly2tri/common/shapes.h
@@ -33,25 +33,7 @@
 #ifndef SHAPES_H
 #define SHAPES_H
 
-#if defined(_WIN32)
-# define COMPILER_DLLEXPORT __declspec(dllexport)
-# define COMPILER_DLLIMPORT __declspec(dllimport)
-#else
-# define COMPILER_DLLEXPORT __attribute__ ((visibility ("default")))
-# define COMPILER_DLLIMPORT __attribute__ ((visibility ("default")))
-#endif
-
-#ifndef P2T_EXPORT
-#  if defined(P2T_DLL_EXPORTS) && defined(P2T_DLL_IMPORTS)
-#    error "Only P2T_DLL_EXPORTS or P2T_DLL_IMPORTS can be defined, not both."
-#  elif defined(P2T_DLL_EXPORTS)
-#    define P2T_EXPORT COMPILER_DLLEXPORT
-#  elif defined(P2T_DLL_IMPORTS)
-#    define P2T_EXPORT COMPILER_DLLIMPORT
-#  else
-#    define P2T_EXPORT
-#  endif
-#endif
+#include "dll_symbol.h"
 
 #include <cmath>
 #include <cstddef>
@@ -62,12 +44,12 @@ namespace p2t {
 
 struct Edge;
 
-struct Point {
+struct P2T_DLL_SYMBOL Point {
 
   double x, y;
 
   /// Default constructor does nothing (for performance).
-  P2T_EXPORT Point()
+  Point()
   {
     x = 0.0;
     y = 0.0;
@@ -80,21 +62,21 @@ struct Point {
   Point(double x, double y);
 
   /// Set this point to all zeros.
-  P2T_EXPORT void set_zero()
+  void set_zero()
   {
     x = 0.0;
     y = 0.0;
   }
 
   /// Set this point to some specified coordinates.
-  P2T_EXPORT void set(double x_, double y_)
+  void set(double x_, double y_)
   {
     x = x_;
     y = y_;
   }
 
   /// Negate this point.
-  P2T_EXPORT Point operator -() const
+  Point operator -() const
   {
     Point v;
     v.set(-x, -y);
@@ -102,34 +84,34 @@ struct Point {
   }
 
   /// Add a point to this point.
-  P2T_EXPORT void operator +=(const Point& v)
+  void operator +=(const Point& v)
   {
     x += v.x;
     y += v.y;
   }
 
   /// Subtract a point from this point.
-  P2T_EXPORT void operator -=(const Point& v)
+  void operator -=(const Point& v)
   {
     x -= v.x;
     y -= v.y;
   }
 
   /// Multiply this point by a scalar.
-  P2T_EXPORT void operator *=(double a)
+  void operator *=(double a)
   {
     x *= a;
     y *= a;
   }
 
   /// Get the length of this point (the norm).
-  P2T_EXPORT double Length() const
+  double Length() const
   {
     return sqrt(x * x + y * y);
   }
 
   /// Convert this point into a unit point. Returns the Length.
-  P2T_EXPORT double Normalize()
+  double Normalize()
   {
     const double len = Length();
     x /= len;
@@ -139,15 +121,15 @@ struct Point {
 
 };
 
-std::ostream& operator<<(std::ostream&, const Point&);
+P2T_DLL_SYMBOL std::ostream& operator<<(std::ostream&, const Point&);
 
 // Represents a simple polygon's edge
-struct Edge {
+struct P2T_DLL_SYMBOL Edge {
 
   Point* p, *q;
 
   /// Constructor
-  P2T_EXPORT Edge(Point& p1, Point& p2) : p(&p1), q(&p2)
+  Edge(Point& p1, Point& p2) : p(&p1), q(&p2)
   {
     if (p1.y > p2.y) {
       q = &p1;
@@ -169,68 +151,68 @@ struct Edge {
 // Triangle-based data structures are know to have better performance than quad-edge structures
 // See: J. Shewchuk, "Triangle: Engineering a 2D Quality Mesh Generator and Delaunay Triangulator"
 //      "Triangulations in CGAL"
-class Triangle {
+class P2T_DLL_SYMBOL Triangle {
 public:
 
 /// Constructor
-P2T_EXPORT Triangle(Point& a, Point& b, Point& c);
+Triangle(Point& a, Point& b, Point& c);
 
 /// Flags to determine if an edge is a Constrained edge
 bool constrained_edge[3];
 /// Flags to determine if an edge is a Delauney edge
 bool delaunay_edge[3];
 
-P2T_EXPORT Point* GetPoint(int index);
-P2T_EXPORT Point* PointCW(const Point& point);
-P2T_EXPORT Point* PointCCW(const Point& point);
-P2T_EXPORT Point* OppositePoint(Triangle& t, const Point& p);
+Point* GetPoint(int index);
+Point* PointCW(const Point& point);
+Point* PointCCW(const Point& point);
+Point* OppositePoint(Triangle& t, const Point& p);
 
-P2T_EXPORT Triangle* GetNeighbor(int index);
-P2T_EXPORT void MarkNeighbor(Point* p1, Point* p2, Triangle* t);
-P2T_EXPORT void MarkNeighbor(Triangle& t);
+Triangle* GetNeighbor(int index);
+void MarkNeighbor(Point* p1, Point* p2, Triangle* t);
+void MarkNeighbor(Triangle& t);
 
-P2T_EXPORT void MarkConstrainedEdge(int index);
-P2T_EXPORT void MarkConstrainedEdge(Edge& edge);
-P2T_EXPORT void MarkConstrainedEdge(Point* p, Point* q);
+void MarkConstrainedEdge(int index);
+void MarkConstrainedEdge(Edge& edge);
+void MarkConstrainedEdge(Point* p, Point* q);
 
-P2T_EXPORT int Index(const Point* p);
-P2T_EXPORT int EdgeIndex(const Point* p1, const Point* p2);
+int Index(const Point* p);
+int EdgeIndex(const Point* p1, const Point* p2);
 
-P2T_EXPORT Triangle* NeighborAcross(const Point& point);
-P2T_EXPORT Triangle* NeighborCW(const Point& point);
-P2T_EXPORT Triangle* NeighborCCW(const Point& point);
-P2T_EXPORT bool GetConstrainedEdgeCCW(const Point& p);
-P2T_EXPORT bool GetConstrainedEdgeCW(const Point& p);
-P2T_EXPORT void SetConstrainedEdgeCCW(const Point& p, bool ce);
-P2T_EXPORT void SetConstrainedEdgeCW(const Point& p, bool ce);
-P2T_EXPORT bool GetDelunayEdgeCCW(const Point& p);
-P2T_EXPORT bool GetDelunayEdgeCW(const Point& p);
-P2T_EXPORT void SetDelunayEdgeCCW(const Point& p, bool e);
-P2T_EXPORT void SetDelunayEdgeCW(const Point& p, bool e);
+Triangle* NeighborAcross(const Point& point);
+Triangle* NeighborCW(const Point& point);
+Triangle* NeighborCCW(const Point& point);
+bool GetConstrainedEdgeCCW(const Point& p);
+bool GetConstrainedEdgeCW(const Point& p);
+void SetConstrainedEdgeCCW(const Point& p, bool ce);
+void SetConstrainedEdgeCW(const Point& p, bool ce);
+bool GetDelunayEdgeCCW(const Point& p);
+bool GetDelunayEdgeCW(const Point& p);
+void SetDelunayEdgeCCW(const Point& p, bool e);
+void SetDelunayEdgeCW(const Point& p, bool e);
 
-P2T_EXPORT bool Contains(const Point* p);
-P2T_EXPORT bool Contains(const Edge& e);
-P2T_EXPORT bool Contains(const Point* p, const Point* q);
-P2T_EXPORT void Legalize(Point& point);
-P2T_EXPORT void Legalize(Point& opoint, Point& npoint);
+bool Contains(const Point* p);
+bool Contains(const Edge& e);
+bool Contains(const Point* p, const Point* q);
+void Legalize(Point& point);
+void Legalize(Point& opoint, Point& npoint);
 /**
  * Clears all references to all other triangles and points
  */
-P2T_EXPORT void Clear();
-P2T_EXPORT void ClearNeighbor(const Triangle *triangle);
-P2T_EXPORT void ClearNeighbors();
-P2T_EXPORT void ClearDelunayEdges();
+void Clear();
+void ClearNeighbor(const Triangle *triangle);
+void ClearNeighbors();
+void ClearDelunayEdges();
 
-P2T_EXPORT inline bool IsInterior();
-P2T_EXPORT inline void IsInterior(bool b);
+inline bool IsInterior();
+inline void IsInterior(bool b);
 
-P2T_EXPORT void DebugPrint();
+void DebugPrint();
 
-P2T_EXPORT bool CircumcicleContains(const Point&) const;
+bool CircumcicleContains(const Point&) const;
 
 private:
 
-P2T_EXPORT bool IsCounterClockwise() const;
+bool IsCounterClockwise() const;
 
 /// Triangle points
 Point* points_[3];
@@ -344,7 +326,7 @@ inline void Triangle::IsInterior(bool b)
 }
 
 /// Is this set a valid delaunay triangulation?
-bool IsDelaunay(const std::vector<p2t::Triangle*>&);
+P2T_DLL_SYMBOL bool IsDelaunay(const std::vector<p2t::Triangle*>&);
 
 }
 
diff --git a/poly2tri/sweep/cdt.h b/poly2tri/sweep/cdt.h
index cadde7d..7e3a45a 100644
--- a/poly2tri/sweep/cdt.h
+++ b/poly2tri/sweep/cdt.h
@@ -32,30 +32,12 @@
 #ifndef CDT_H
 #define CDT_H
 
-#if defined(_WIN32)
-# define COMPILER_DLLEXPORT __declspec(dllexport)
-# define COMPILER_DLLIMPORT __declspec(dllimport)
-#else
-# define COMPILER_DLLEXPORT __attribute__ ((visibility ("default")))
-# define COMPILER_DLLIMPORT __attribute__ ((visibility ("default")))
-#endif
-
-#ifndef P2T_EXPORT
-#  if defined(P2T_DLL_EXPORTS) && defined(P2T_DLL_IMPORTS)
-#    error "Only P2T_DLL_EXPORTS or P2T_DLL_IMPORTS can be defined, not both."
-#  elif defined(P2T_DLL_EXPORTS)
-#    define P2T_EXPORT COMPILER_DLLEXPORT
-#  elif defined(P2T_DLL_IMPORTS)
-#    define P2T_EXPORT COMPILER_DLLIMPORT
-#  else
-#    define P2T_EXPORT
-#  endif
-#endif
-
 #include "advancing_front.h"
 #include "sweep_context.h"
 #include "sweep.h"
 
+#include "../common/dll_symbol.h"
+
 /**
  *
  * @author Mason Green <mason.green@gmail.com>
@@ -64,7 +46,7 @@
 
 namespace p2t {
 
-class CDT
+class P2T_DLL_SYMBOL CDT
 {
 public:
 
@@ -73,41 +55,41 @@ public:
    *
    * @param polyline
    */
-  P2T_EXPORT CDT(const std::vector<Point*>& polyline);
+  CDT(const std::vector<Point*>& polyline);
 
    /**
    * Destructor - clean up memory
    */
-  P2T_EXPORT ~CDT();
+  ~CDT();
 
   /**
    * Add a hole
    *
    * @param polyline
    */
-  P2T_EXPORT void AddHole(const std::vector<Point*>& polyline);
+  void AddHole(const std::vector<Point*>& polyline);
 
   /**
    * Add a steiner point
    *
    * @param point
    */
-  P2T_EXPORT void AddPoint(Point* point);
+  void AddPoint(Point* point);
 
   /**
    * Triangulate - do this AFTER you've added the polyline, holes, and Steiner points
    */
-  P2T_EXPORT void Triangulate();
+  void Triangulate();
 
   /**
    * Get CDT triangles
    */
-  P2T_EXPORT std::vector<Triangle*> GetTriangles();
+  std::vector<Triangle*> GetTriangles();
 
   /**
    * Get triangle map
    */
-  P2T_EXPORT std::list<Triangle*> GetMap();
+  std::list<Triangle*> GetMap();
 
   private: