diff -wpruN --no-dereference '--exclude=*.orig' a~/ext/openssl/ossl_ssl.c a/ext/openssl/ossl_ssl.c
--- a~/ext/openssl/ossl_ssl.c	1970-01-01 00:00:00
+++ a/ext/openssl/ossl_ssl.c	1970-01-01 00:00:00
@@ -1956,6 +1956,7 @@ ossl_ssl_read_internal(int argc, VALUE *
             io_wait_writable(fptr);
             continue;
           case SSL_ERROR_WANT_READ:
+wantread:
             if (nonblock) {
                 rb_str_unlocktmp(str);
                 if (no_exception_p(opts)) { return sym_wait_readable; }
@@ -1966,7 +1967,9 @@ ossl_ssl_read_internal(int argc, VALUE *
           case SSL_ERROR_SYSCALL:
             if (!ERR_peek_error()) {
                 rb_str_unlocktmp(str);
-                if (errno)
+                if (errno == EAGAIN)
+                    goto wantread;
+                else if (errno)
                     rb_sys_fail(0);
                 else {
                     /*