diff --git a/src/wolfio.c b/src/wolfio.c
index 3462e2b3e..f7e35d9a8 100644
--- a/src/wolfio.c
+++ b/src/wolfio.c
@@ -2225,4 +2225,78 @@ int uIPGenerateCookie(WOLFSSL* ssl, byte *buf, int sz, void *_ctx)
 
 #endif /* WOLFSSL_UIP */
 
+#ifdef WOLFSSL_GNRC
+
+#include <net/sock.h>
+#include <net/sock/tcp.h>
+#include <stdio.h>
+
+/* GNRC TCP/IP port, using the native tcp/udp socket api.
+ * TCP and UDP are currently supported with the callbacks below.
+ *
+ */
+/* The GNRC tcp send callback
+ * return : bytes sent, or error
+ */
+
+int GNRC_SendTo(WOLFSSL* ssl, char* buf, int sz, void* _ctx)
+{
+    sock_tls_t *ctx = (sock_tls_t *)_ctx;
+    int ret = 0;
+    (void)ssl;
+    ret = sock_udp_send(&ctx->conn.udp, (unsigned char *)buf, sz, &ctx->peer_addr);
+    if (ret <= 0)
+        return 0;
+    return ret;
+}
+
+/* The GNRC TCP/IP receive callback
+ *  return : nb bytes read, or error
+ */
+int GNRC_Receive(WOLFSSL *ssl, char *buf, int sz, void *_ctx)
+{
+    sock_udp_ep_t ep;
+    int ret;
+    uint32_t timeout = wolfSSL_dtls_get_current_timeout(ssl) * 1000000;
+    sock_tls_t *ctx = (sock_tls_t *)_ctx;
+    if (!ctx)
+        return -1;
+    (void)ssl;
+    if (wolfSSL_get_using_nonblock(ctx->ssl)) {
+        timeout = 0;
+    }
+    ret = sock_udp_recv(&ctx->conn.udp, buf, sz, timeout, &ep);
+    if (ret > 0) {
+        if (ctx->peer_addr.port == 0)
+            XMEMCPY(&ctx->peer_addr, &ep, sizeof(sock_udp_ep_t));
+    }
+    if (ret == -ETIMEDOUT) {
+        return WOLFSSL_CBIO_ERR_WANT_READ;
+    }
+    return ret;
+}
+
+/* GNRC DTLS Generate Cookie callback
+ *  return : number of bytes copied into buf, or error
+ */
+int GNRC_GenerateCookie(WOLFSSL* ssl, byte *buf, int sz, void *_ctx)
+{
+    sock_tls_t *ctx = (sock_tls_t *)_ctx;
+    byte token[32];
+    byte digest[WC_SHA_DIGEST_SIZE];
+    int  ret = 0;
+    (void)ssl;
+    XMEMSET(token, 0, sizeof(token));
+    XMEMCPY(token, &ctx->peer_addr, sizeof(sock_udp_ep_t));
+    ret = wc_ShaHash(token, sizeof(sock_udp_ep_t), digest);
+    if (ret != 0)
+        return ret;
+    if (sz > WC_SHA_DIGEST_SIZE)
+        sz = WC_SHA_DIGEST_SIZE;
+    XMEMCPY(buf, digest, sz);
+    return sz;
+}
+
+#endif /* WOLFSSL_GNRC */
+
 #endif /* WOLFCRYPT_ONLY */
diff --git a/wolfssl/wolfcrypt/settings.h b/wolfssl/wolfcrypt/settings.h
index 6d7c283dc..34e2be78a 100644
--- a/wolfssl/wolfcrypt/settings.h
+++ b/wolfssl/wolfcrypt/settings.h
@@ -527,7 +527,6 @@
 #ifdef WOLFSSL_RIOT_OS
     #define NO_WRITEV
     #define TFM_NO_ASM
-    #define USE_FAST_MATH
     #define NO_FILESYSTEM
     #define USE_CERT_BUFFERS_2048
 #endif
diff --git a/wolfssl/wolfio.h b/wolfssl/wolfio.h
index 27290d0dc..fb50dc603 100644
--- a/wolfssl/wolfio.h
+++ b/wolfssl/wolfio.h
@@ -133,7 +133,8 @@
             #include "rtipapi.h"  /* errno */
             #include "socket.h"
         #elif !defined(DEVKITPRO) && !defined(WOLFSSL_PICOTCP) \
-                && !defined(WOLFSSL_CONTIKI) && !defined(WOLFSSL_WICED)
+                && !defined(WOLFSSL_CONTIKI) && !defined(WOLFSSL_WICED) \
+                && !defined(WOLFSSL_GNRC) && !defined(WOLFSSL_RIOT_OS)
             #include <sys/socket.h>
             #include <arpa/inet.h>
             #include <netinet/in.h>
@@ -491,6 +492,37 @@ WOLFSSL_API void wolfSSL_SetIOWriteFlags(WOLFSSL* ssl, int flags);
 
 #endif
 
+#ifdef WOLFSSL_GNRC
+    #include <sock_types.h>
+    #include <net/gnrc.h>
+    #include <net/af.h>
+    #include <net/sock.h>
+    #include <net/gnrc/tcp.h>
+    #include <net/gnrc/udp.h>
+
+    struct gnrc_wolfssl_ctx {
+        union socket_connector {
+        #ifdef MODULE_SOCK_TCP
+            sock_tcp_t tcp;
+        #endif
+            sock_udp_t udp;
+        } conn;
+        WOLFSSL_CTX *ctx;
+        WOLFSSL *ssl;
+
+        int closing;
+        struct _sock_tl_ep peer_addr;
+    };
+
+    typedef struct gnrc_wolfssl_ctx sock_tls_t;
+
+    WOLFSSL_LOCAL int GNRC_Receive(WOLFSSL* ssl, char* buf, int sz,
+                                     void* ctx);
+    WOLFSSL_LOCAL int GNRC_SendTo(WOLFSSL* ssl, char* buf, int sz, void* ctx);
+
+#endif
+
+
 #ifdef WOLFSSL_DTLS
     typedef int (*CallbackGenCookie)(WOLFSSL* ssl, unsigned char* buf, int sz,
                                      void* ctx);