diff --git a/utlise.h b/utlise.h
index 192e56181d89f30007e5b827cfca921e504d658b..6a476cd981a42004d46c4c9ce94cc0bb28b90613 100644
--- a/utlise.h
+++ b/utlise.h
@@ -6,6 +6,10 @@ static inline void mem_usage();
 void check_correctness(int n, int *row_ptr, int *col_idx, double *val, double *x, double *b);
 
 void check_correctness_complex(int n, int *row_ptr, int *col_idx, double *val, double *val_v, double *x, double *xi, double *b, double *bi);
+// check answer function(long double)
+void check_correctness_long(int n, int *row_ptr, int *col_idx, double *val, double *x, double *b);
+
+void check_correctness_complex_long(int n, int *row_ptr, int *col_idx, double *val, double *val_v, double *x, double *xi, double *b, double *bi);
 
 // store vector function
 void store_x(int n, double *x, char *filename);