diff --git a/library/debug.c b/library/debug.c
index 3164ad7..940a2d2 100644
--- a/library/debug.c
+++ b/library/debug.c
@@ -108,6 +108,14 @@
     if( ssl->conf->f_dbg == NULL || level > debug_threshold )
         return;
 
+    /*
+     * With non-blocking I/O and examples that just retry immediately,
+     * the logs would be quickly flooded with WANT_READ, so ignore that.
+     * Don't ignore WANT_WRITE however, since is is usually rare.
+     */
+    if( ret == MBEDTLS_ERR_SSL_WANT_READ )
+        return;
+
     if( debug_log_mode == MBEDTLS_DEBUG_LOG_FULL )
         idx = mbedtls_snprintf( str, maxlen, "%s(%04d): ", file, line );