diff --git a/lib/geometry.h b/lib/geometry.h
index dd49769..af133ad 100755
--- a/lib/geometry.h
+++ b/lib/geometry.h
@@ -8,7 +8,7 @@ Defines the TESSEROID, SPHERE, and PRISM structures.
 
 
 /* Store information on a tesseroid */
-typedef struct tess_struct {
+typedef struct magtess_struct {
     /* s, n, w, e in degrees. r1 and r2 are the smaller and larger radius */
     double density; /* in SI units */
     double w; /* western longitude border in degrees */