diff --git a/configure.ac b/configure.ac
index 2e6a186..5116246 100644
--- a/configure.ac
+++ b/configure.ac
@@ -160,6 +160,7 @@ EXPRESS_LIBS="${EXPRESS_LIBS} ${EXP_LIBS}"
 
 AC_FUNC_ALLOCA
 
+AC_CHECK_FUNCS([geuid getuid])
 
 AC_CONFIG_FILES([
 Makefile