diff --git a/configure.ac b/configure.ac
index 43e13ba..39c2f76 100644
--- a/configure.ac
+++ b/configure.ac
@@ -23,6 +23,13 @@ AC_PROG_CC
  # libosmocore (codec module)
 PKG_CHECK_MODULES(LIBOSMOCODEC, libosmocodec >= 0.1.25)
 
+ # opencore-amrnb for AMR and EFR decoding
+found_opencore_amrnb=yes
+PKG_CHECK_MODULES(OPENCORE_AMRNB, opencore-amrnb >= 0.1.0, , found_libgsm=no)
+if test "$found_opencore_amrnb" = yes; then
+	AC_DEFINE(HAVE_OPENCORE_AMRNB, 1, [Define to 1 if OpenCore AMR-NB library is available])
+fi
+
  # libgsm for FR decoding
 found_libgsm=yes
 AC_CHECK_HEADERS(gsm/gsm.h, ,
diff --git a/src/Makefile.am b/src/Makefile.am
index dc37076..dedb3f0 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,6 +1,6 @@
 INCLUDES = $(all_includes) -I$(top_srcdir)/include -I$(top_builddir)
-AM_CFLAGS=-Wall $(LIBOSMOCODEC_CFLAGS)
-AM_LDFLAGS=$(LIBOSMOCODEC_LIBS) ${LIBGSM_LIBS}
+AM_CFLAGS=-Wall $(LIBOSMOCODEC_CFLAGS) ${OPENCORE_AMRNB_CFLAGS}
+AM_LDFLAGS=$(LIBOSMOCODEC_LIBS) ${OPENCORE_AMRNB_LIBS} ${LIBGSM_LIBS}
 
 bin_PROGRAMS = gapk
 gapk_SOURCES =	main.c	\
diff --git a/src/codec_efr.c b/src/codec_efr.c
index 6c9b59e..ca5225c 100644
--- a/src/codec_efr.c
+++ b/src/codec_efr.c
@@ -19,9 +19,95 @@
 
 #include <gapk/codecs.h>
 
+#include "config.h"
+
+
+#ifdef HAVE_OPENCORE_AMRNB
+
+#include <stdlib.h>
+
+#include <interf_dec.h>
+#include <interf_enc.h>
+
+
+struct codec_efr_state {
+	void *encoder;
+	void *decoder;
+};
+
+
+static void *
+codec_efr_init(void)
+{
+	struct codec_efr_state *st;
+
+	st = calloc(1, sizeof(*st));
+	if (!st)
+		return NULL;
+
+	st->encoder = Encoder_Interface_init(0);
+	st->decoder = Decoder_Interface_init();
+
+	return (void *)st;
+}
+
+static void
+codec_efr_exit(void *state)
+{
+	struct codec_efr_state *st = state;
+
+	Decoder_Interface_exit(st->decoder);
+	Encoder_Interface_exit(st->encoder);
+
+	return;
+}
+
+static int
+codec_efr_encode(void *state, uint8_t *cod, const uint8_t *pcm)
+{
+	struct codec_efr_state *st = state;
+	int rv;
+
+	rv = Encoder_Interface_Encode(
+		st->encoder,
+		MR122,
+		(const short*) pcm,
+		(unsigned char*) cod,
+		1
+	);
+
+	return rv;
+}
+
+static int
+codec_efr_decode(void *state, uint8_t *pcm, const uint8_t *cod)
+{
+	struct codec_efr_state *st = state;
+
+	Decoder_Interface_Decode(
+		st->decoder,
+		(const unsigned char*) cod,
+		(short *) pcm,
+		0
+	);
+
+	return 0;
+}
+
+#endif /* HAVE_OPENCORE_AMRNB */
+
+
 const struct codec_desc codec_efr_desc = {
 	.type = CODEC_EFR,
 	.name = "efr",
 	.description = "GSM 06.60 Enhanced Full Rate codec",
 	.canon_frame_len = 31,
+#ifdef HAVE_OPENCORE_AMRNB
+	.codec_enc_format_type = FMT_AMR_EFR,
+	.codec_dec_format_type = FMT_AMR_EFR,
+	.codec_init = codec_efr_init,
+	.codec_exit = codec_efr_exit,
+	.codec_encode = codec_efr_encode,
+	.codec_decode = codec_efr_decode,
+#endif
 };