diff --git a/c/coreslam.c b/c/coreslam.c
index 09ee999..b6dd380 100644
--- a/c/coreslam.c
+++ b/c/coreslam.c
@@ -433,10 +433,11 @@ void
 scan_update(
         scan_t * scan,
         float * lidar_angles_deg,
-        int * lidar_distances_mm,
-        double hole_width_mm,
-        double velocities_dxy_mm,
-        double velocities_dtheta_degrees)
+        int *   lidar_distances_mm,
+        int     scan_size,
+        double  hole_width_mm,
+        double  velocities_dxy_mm,
+        double  velocities_dtheta_degrees)
 {    
     /* Take velocity into account */
     int degrees_per_second = (int)(scan->rate_hz * 360);
diff --git a/c/coreslam.h b/c/coreslam.h
index c6c6d93..75fe163 100644
--- a/c/coreslam.h
+++ b/c/coreslam.h
@@ -134,7 +134,8 @@ void
 scan_update(
     scan_t * scan, 
     float * lidar_angles_deg,
-    int * lidar_distances_mm, 
+    int   * lidar_distances_mm, 
+    int     scan_size, 
     double hole_width_mm,
     double velocities_dxy_mm,
     double velocities_dtheta_degrees);
diff --git a/cpp/Scan.cpp b/cpp/Scan.cpp
index 6068d8f..415436d 100644
--- a/cpp/Scan.cpp
+++ b/cpp/Scan.cpp
@@ -82,6 +82,7 @@ Scan::update(
         this->scan,
         NULL, // no support for angles/interpolation yet
         scanvals_mm,
+        this->scan->size,// no support for angles/interpolation yet
         hole_width_millimeters,
         poseChange.dxy_mm,
         poseChange.dtheta_degrees);
diff --git a/java/edu/wlu/cs/levy/breezyslam/components/jnibreezyslam_components.c b/java/edu/wlu/cs/levy/breezyslam/components/jnibreezyslam_components.c
index fa8edfc..7e5f6d9 100644
--- a/java/edu/wlu/cs/levy/breezyslam/components/jnibreezyslam_components.c
+++ b/java/edu/wlu/cs/levy/breezyslam/components/jnibreezyslam_components.c
@@ -127,7 +127,7 @@ JNIEXPORT void JNICALL Java_edu_wlu_cs_levy_breezyslam_components_Scan_update (J
     jint * lidar_mm_c = (*env)->GetIntArrayElements(env, lidar_mm, 0);
 
     // no support for angles/interpolation yet
-    scan_update(scan, NULL, lidar_mm_c, hole_width_mm, velocities_dxy_mm, velocities_dtheta_degrees);
+    scan_update(scan, NULL, lidar_mm_c, scan->size, hole_width_mm, velocities_dxy_mm, velocities_dtheta_degrees);
 
     (*env)->ReleaseIntArrayElements(env, lidar_mm, lidar_mm_c, 0);
 }
diff --git a/matlab/mex_breezyslam.c b/matlab/mex_breezyslam.c
index cd45295..8ae2147 100644
--- a/matlab/mex_breezyslam.c
+++ b/matlab/mex_breezyslam.c
@@ -192,7 +192,7 @@ static void _scan_update(const mxArray * prhs[])
     double * velocities = mxGetPr(prhs[4]);
     
     /* no support for angles/interpolation yet */
-    scan_update(scan, NULL, lidar_mm, hole_width_mm, velocities[0], velocities[1]);
+    scan_update(scan, NULL, lidar_mm, scan->size, hole_width_mm, velocities[0], velocities[1]);
 }
 
 static void _randomizer_init(mxArray *plhs[], const mxArray * prhs[])
diff --git a/python/pybreezyslam.c b/python/pybreezyslam.c
index 4aa5420..772a216 100644
--- a/python/pybreezyslam.c
+++ b/python/pybreezyslam.c
@@ -349,6 +349,7 @@ Scan_update(Scan *self, PyObject *args, PyObject *kwds)
             &self->scan, 
             NULL,
             self->lidar_distances_mm, 
+            PyList_Size(py_lidar),
             hole_width_mm,
             dxy_mm,
             dtheta_degrees);