diff --git a/lib/url.c b/lib/url.c
index 0c47b2e0ff3c62e7f895fb4eb95d184c4f0c45fb..dcd0065a483e9f393ed3fdaf1252d97c76c16e71 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -143,7 +143,9 @@ static unsigned int ConnectionStore(struct SessionHandle *data,
 #ifndef RETSIGTYPE
 #define RETSIGTYPE void
 #endif
+#ifdef HAVE_SIGSETJMP
 extern sigjmp_buf curl_jmpenv;
+#endif
 static
 RETSIGTYPE alarmfunc(int signal)
 {