diff --git a/decoder/ih264d_parse_bslice.c b/decoder/ih264d_parse_bslice.c
index 4418429..f087f8d 100644
--- a/decoder/ih264d_parse_bslice.c
+++ b/decoder/ih264d_parse_bslice.c
@@ -1399,7 +1399,8 @@ WORD32 ih264d_parse_bslice(dec_struct_t * ps_dec, UWORD16 u2_first_mb_in_slice)
         {
             u1_max_ref_idx = MAX_FRAMES << 1;
         }
-        if((u4_temp > u1_max_ref_idx) || (ui_temp1 > u1_max_ref_idx))
+        if((u4_temp > u1_max_ref_idx) || (ui_temp1 > u1_max_ref_idx)
+                        || (u4_temp < 1) || (ui_temp1 < 1))
         {
             return ERROR_NUM_REF;
         }
diff --git a/decoder/ih264d_parse_pslice.c b/decoder/ih264d_parse_pslice.c
index d6b0f23..9b9256b 100644
--- a/decoder/ih264d_parse_pslice.c
+++ b/decoder/ih264d_parse_pslice.c
@@ -1961,7 +1961,7 @@ WORD32 ih264d_parse_pslice(dec_struct_t *ps_dec, UWORD16 u2_first_mb_in_slice)
 
 
         UWORD8 u1_max_ref_idx = MAX_FRAMES << u1_field_pic_flag;
-        if(u4_temp > u1_max_ref_idx)
+        if(u4_temp > u1_max_ref_idx || u4_temp < 1)
         {
             return ERROR_NUM_REF;
         }