diff --git a/src/protocol/messages.c b/src/protocol/messages.c
index b3ddbec..bdb8a55 100644
--- a/src/protocol/messages.c
+++ b/src/protocol/messages.c
@@ -90,20 +90,24 @@ void cr_send_to_runner(const criterion_protocol_msg *message) {
         abort();
     }
 
+    struct nn_pollfd pfd = {
+        .fd = g_client_socket,
+        .events = NN_POLLIN,
+    };
+
+    if (nn_poll(&pfd, 1, INT_MAX) != 1) {
+        criterion_perror("Could not poll for ack: %s.\n", nn_strerror(errno));
+        abort();
+    }
+
     unsigned char *buf = NULL;
-    int read = 0;
+    int read = nn_recv(g_client_socket, &buf, NN_MSG, 0);
 
-    do {
-        read = nn_recv(g_client_socket, &buf, NN_MSG, 0);
-
-        if (read <= 0) {
-            if (read == -1 && errno == EFSM)
-                continue;
-            criterion_perror("Could not read ack: %s.\n", nn_strerror(errno));
-            abort();
-        }
-        break;
-    } while (true);
+    if (read <= 0) {
+        criterion_perror("Could not read ack: %s.\n",
+                read == -1 ? nn_strerror(errno) : "No data");
+        abort();
+    }
 
     criterion_protocol_ack ack;
     pb_istream_t stream = pb_istream_from_buffer(buf, read);