diff --git a/src/de/mod.rs b/src/de/mod.rs
index f2ccbe2b..d1c5048a 100644
--- a/src/de/mod.rs
+++ b/src/de/mod.rs
@@ -758,7 +758,7 @@ where
 
 #[cfg(test)]
 mod tests {
-
+    use core::str::FromStr;
     use serde_derive::Deserialize;
 
     #[derive(Debug, Deserialize, PartialEq)]