diff --git a/src/plastimatch/base/direction_cosines.h b/src/plastimatch/base/direction_cosines.h
index 8de7d45dd..11f61eda4 100644
--- a/src/plastimatch/base/direction_cosines.h
+++ b/src/plastimatch/base/direction_cosines.h
@@ -8,13 +8,13 @@
 #include <string>
 #include <stdio.h>
 
+#include "itk_image.h"
 #include "plm_math.h"
 
 #define DIRECTION_COSINES_IDENTITY_THRESH 1e-9
 #define DIRECTION_COSINES_EQUALITY_THRESH 1e-9
 
 namespace itk { template<class T, unsigned int NRows, unsigned int NColumns> class Matrix; }
-typedef itk::Matrix < double, 3, 3 > DirectionType;
 
 class Direction_cosines_private;