diff --git a/src/asn_codecs_prim.h b/src/asn_codecs_prim.h
new file mode 100644
index 0000000..0f683fd
--- /dev/null
+++ b/src/asn_codecs_prim.h
@@ -0,0 +1,53 @@
+/*-
+ * Copyright (c) 2004 Lev Walkin <vlm@lionet.info>. All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#ifndef	ASN_CODECS_PRIM_H
+#define	ASN_CODECS_PRIM_H
+
+#include <asn_application.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct ASN__PRIMITIVE_TYPE_s {
+	uint8_t *buf;	/* Buffer with consecutive primitive encoding bytes */
+	int size;	/* Size of the buffer */
+} ASN__PRIMITIVE_TYPE_t;	/* Do not use this type directly! */
+
+asn_struct_free_f ASN__PRIMITIVE_TYPE_free;
+ber_type_decoder_f ber_decode_primitive;
+der_type_encoder_f der_encode_primitive;
+
+/*
+ * A callback specification for the xer_decode_primitive() function below.
+ */
+enum xer_pbd_rval {
+	XPBD_SYSTEM_FAILURE,	/* System failure (memory shortage, etc) */
+	XPBD_DECODER_LIMIT,	/* Hit some decoder limitation or deficiency */
+	XPBD_BROKEN_ENCODING,	/* Encoding of a primitive body is broken */
+	XPBD_NOT_BODY_IGNORE,	/* Not a body format, but safe to ignore */
+	XPBD_BODY_CONSUMED	/* Body is recognized and consumed */
+};
+typedef enum xer_pbd_rval (xer_primitive_body_decoder_f)
+	(asn_TYPE_descriptor_t *td, void *struct_ptr,
+		const void *chunk_buf, size_t chunk_size);
+
+/*
+ * Specific function to decode simple primitive types.
+ * Also see xer_decode_general() in xer_decoder.h
+ */
+asn_dec_rval_t xer_decode_primitive(asn_codec_ctx_t *opt_codec_ctx,
+	asn_TYPE_descriptor_t *type_descriptor,
+	void **struct_ptr, size_t struct_size,
+	const char *opt_mname,
+	const void *buf_ptr, size_t size,
+	xer_primitive_body_decoder_f *prim_body_decoder
+);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* ASN_CODECS_PRIM_H */