diff --git a/libfprint/nbis/mindtct/contour.c b/libfprint/nbis/mindtct/contour.c
index 3361047..5d802c2 100644
--- a/libfprint/nbis/mindtct/contour.c
+++ b/libfprint/nbis/mindtct/contour.c
@@ -107,6 +107,8 @@ int allocate_contour(int **ocontour_x, int **ocontour_y,
 {
    int *contour_x, *contour_y, *contour_ex, *contour_ey;
 
+   ASSERT_SIZE_MUL(ncontour, sizeof(int));
+
    /* Allocate contour's x-coord list. */
    contour_x = (int *)malloc(ncontour*sizeof(int));
    /* If allocation error... */