diff --git a/skeletons/asn_codecs_prim.c b/skeletons/asn_codecs_prim.c
index e0b545a..8791475 100644
--- a/skeletons/asn_codecs_prim.c
+++ b/skeletons/asn_codecs_prim.c
@@ -143,12 +143,38 @@
 	int want_more;
 };
 
+/*
+ * Check whether this buffer consists of entirely XER whitespace characters.
+ */
+static int
+xer_decode__check_whitespace(void *chunk_buf, size_t chunk_size) {
+	char *p = (char *)chunk_buf;
+	char *pend = p + chunk_size;
+	for(; p < pend; p++) {
+		switch(*p) {
+		/* X.693, #8.1.4
+		 * HORISONTAL TAB (9)
+		 * LINE FEED (10)
+		 * CARRIAGE RETURN (13)
+		 * SPACE (32)
+		 */
+		case 0x09: case 0x0a: case 0x0d: case 0x20:
+			break;
+		default:
+			return 0;
+		}
+	}
+	return 1;	/* All whitespace */
+}
+
 static int
 xer_decode__unexpected_tag(void *key, void *chunk_buf, size_t chunk_size) {
 	struct xdp_arg_s *arg = (struct xdp_arg_s *)key;
 	ssize_t decoded;
 
 	if(arg->decoded_something) {
+		if(xer_decode__check_whitespace(chunk_buf, chunk_size))
+			return chunk_size;
 		/*
 		 * Decoding was done once already. Prohibit doing it again.
 		 */
@@ -171,6 +197,8 @@
 	ssize_t decoded;
 
 	if(arg->decoded_something) {
+		if(xer_decode__check_whitespace(chunk_buf, chunk_size))
+			return chunk_size;
 		/*
 		 * Decoding was done once already. Prohibit doing it again.
 		 */