diff --git a/skimage/_shared/geometry.pxd b/skimage/_shared/geometry.pxd
index b228b23a..afdc6b5b 100644
--- a/skimage/_shared/geometry.pxd
+++ b/skimage/_shared/geometry.pxd
@@ -1,6 +1,5 @@
-
-cdef inline unsigned char point_in_polygon(int nr_verts, double *xp, double *yp,
-                                           double x, double y)
+cdef unsigned char point_in_polygon(int nr_verts, double *xp, double *yp,
+                                    double x, double y)
 
 cdef void points_in_polygon(int nr_verts, double *xp, double *yp,
                             int nr_points, double *x, double *y,