diff --git a/src/map/albersequal.cpp b/src/map/albersequal.cpp
index 0a0e1858..cedde0d4 100644
--- a/src/map/albersequal.cpp
+++ b/src/map/albersequal.cpp
@@ -41,6 +41,7 @@ Defense.
 
 */
 
+#include "ellipsoid.h"
 #include "albersequal.h"
 
 
diff --git a/src/map/albersequal.h b/src/map/albersequal.h
index 11b9a63a..fb6af6b0 100644
--- a/src/map/albersequal.h
+++ b/src/map/albersequal.h
@@ -1,9 +1,10 @@
 #ifndef ALBERSEQUAL_H
 #define ALBERSEQUAL_H
 
-#include "ellipsoid.h"
 #include "ct.h"
 
+class Ellipsoid;
+
 class AlbersEqual : public CT
 {
 public:
diff --git a/src/map/lambertazimuthal.cpp b/src/map/lambertazimuthal.cpp
index 0156f489..3e1047c1 100644
--- a/src/map/lambertazimuthal.cpp
+++ b/src/map/lambertazimuthal.cpp
@@ -1,3 +1,5 @@
+#include <cmath>
+#include "ellipsoid.h"
 #include "lambertazimuthal.h"
 
 #define sin2(x) (sin(x) * sin(x))
diff --git a/src/map/lambertazimuthal.h b/src/map/lambertazimuthal.h
index fb1f42ec..5025299a 100644
--- a/src/map/lambertazimuthal.h
+++ b/src/map/lambertazimuthal.h
@@ -1,9 +1,10 @@
 #ifndef LAMBERTAZIMUTHAL_H
 #define LAMBERTAZIMUTHAL_H
 
-#include "ellipsoid.h"
 #include "ct.h"
 
+class Ellipsoid;
+
 class LambertAzimuthal : public CT
 {
 public:
diff --git a/src/map/lambertconic.cpp b/src/map/lambertconic.cpp
index 93b9b435..af9416ba 100644
--- a/src/map/lambertconic.cpp
+++ b/src/map/lambertconic.cpp
@@ -42,6 +42,7 @@ Defense.
 */
 
 #include <cmath>
+#include "ellipsoid.h"
 #include "lambertconic.h"
 
 #ifndef M_PI_2
diff --git a/src/map/lambertconic.h b/src/map/lambertconic.h
index 25aa8b93..1ebbe030 100644
--- a/src/map/lambertconic.h
+++ b/src/map/lambertconic.h
@@ -1,9 +1,10 @@
 #ifndef LAMBERTCONIC_H
 #define LAMBERTCONIC_H
 
-#include "ellipsoid.h"
 #include "ct.h"
 
+class Ellipsoid;
+
 class LambertConic1 : public CT
 {
 public:
diff --git a/src/map/transversemercator.h b/src/map/transversemercator.h
index 13c78bd4..1c11f319 100644
--- a/src/map/transversemercator.h
+++ b/src/map/transversemercator.h
@@ -2,7 +2,8 @@
 #define TRANSVERSEMERCATOR_H
 
 #include "ct.h"
-#include "ellipsoid.h"
+
+class Ellipsoid;
 
 class TransverseMercator : public CT
 {