diff --git a/libfaad/syntax.c b/libfaad/syntax.c
index f8e808c2..e7fb1138 100644
--- a/libfaad/syntax.c
+++ b/libfaad/syntax.c
@@ -344,6 +344,12 @@ static void decode_sce_lfe(NeAACDecStruct *hDecoder,
        can become 2 when some form of Parametric Stereo coding is used
     */
 
+    if (hDecoder->frame && hDecoder->element_id[hDecoder->fr_ch_ele] != id_syn_ele) {
+        /* element inconsistency */
+        hInfo->error = 21;
+        return;
+    }
+
     /* save the syntax element id */
     hDecoder->element_id[hDecoder->fr_ch_ele] = id_syn_ele;
 
@@ -395,6 +401,12 @@ static void decode_cpe(NeAACDecStruct *hDecoder, NeAACDecFrameInfo *hInfo, bitfi
         return;
     }
 
+    if (hDecoder->frame && hDecoder->element_id[hDecoder->fr_ch_ele] != id_syn_ele) {
+        /* element inconsistency */
+        hInfo->error = 21;
+        return;
+    }
+
     /* save the syntax element id */
     hDecoder->element_id[hDecoder->fr_ch_ele] = id_syn_ele;