diff --git a/src/protocol/protocol.c b/src/protocol/protocol.c
index 3206888..271b0c0 100644
--- a/src/protocol/protocol.c
+++ b/src/protocol/protocol.c
@@ -23,8 +23,6 @@
  */
 #include <pb_encode.h>
 #include <pb_decode.h>
-#include <nanomsg/nn.h>
-#include <nanomsg/pipeline.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdio.h>
@@ -32,35 +30,4 @@
 #include "criterion/internal/common.h"
 #include "protocol.h"
 
-static bool write_fd_callback(pb_ostream_t *stream, const uint8_t *buf, size_t count) {
-    int fd = (intptr_t) stream->state;
-    ssize_t result = write(fd, buf, count);
-
-    if (result < 0)
-        return false;
-    return (size_t) result == count;
-}
-
-static bool read_fd_callback(pb_istream_t *stream, uint8_t *buf, size_t count) {
-    int fd = (intptr_t) stream->state;
-    ssize_t result = read(fd, buf, count);
-
-    if (result < 0)
-        return false;
-
-    if ((size_t) result < count)
-        stream->bytes_left = result;
-    return (size_t) result == count;
-}
-
-pb_ostream_t pb_ostream_from_fd(int fd) {
-    pb_ostream_t stream = {&write_fd_callback, (void*)(intptr_t) fd, SIZE_MAX, 0, NULL};
-    return stream;
-}
-
-pb_istream_t pb_istream_from_fd(int fd) {
-    pb_istream_t stream = {&read_fd_callback, (void*)(intptr_t) fd, SIZE_MAX, NULL};
-    return stream;
-}
-
 volatile bool is_extern_worker = false;
diff --git a/src/protocol/protocol.h b/src/protocol/protocol.h
index 4e4db88..60a4616 100644
--- a/src/protocol/protocol.h
+++ b/src/protocol/protocol.h
@@ -34,12 +34,6 @@ enum protocol_version {
     PROTOCOL_V1 = 1,
 };
 
-bool pb_write_string(pb_ostream_t *stream, const pb_field_t *field, void * const *arg);
-bool pb_read_string(pb_istream_t *stream, const pb_field_t *field, void **arg);
-
-pb_ostream_t pb_ostream_from_fd(int fd);
-pb_istream_t pb_istream_from_fd(int fd);
-
 extern volatile bool is_extern_worker;
 
 # define criterion_message_set_id(Msg)                                      \