diff --git a/build.rs b/build.rs
index 997df66..e885975 100644
--- a/build.rs
+++ b/build.rs
@@ -4,9 +4,7 @@ use std::env;
 fn main() {
     let ac = autocfg::new();
 
-    if ac.probe_type("i128") {
+    if ac.probe_type("i128") || env::var_os("CARGO_FEATURE_I128").is_some() {
         println!("cargo:rustc-cfg=has_i128");
-    } else if env::var_os("CARGO_FEATURE_I128").is_some() {
-        panic!("i128 support was not detected!");
     }
-}
\ No newline at end of file
+}