diff --git a/diesel/src/pg/types/array.rs b/diesel/src/pg/types/array.rs
index 8afcf878151f..c3141cb5ca7d 100644
--- a/diesel/src/pg/types/array.rs
+++ b/diesel/src/pg/types/array.rs
@@ -101,7 +101,7 @@ where
         out.write_i32::<NetworkEndian>(flags)?;
         let element_oid = Pg::metadata(out.metadata_lookup()).oid()?;
         out.write_u32::<NetworkEndian>(element_oid)?;
-        out.write_i32::<NetworkEndian>(self.len() as i32)?;
+        out.write_i32::<NetworkEndian>(self.len().try_into()?)?;
         let lower_bound = 1;
         out.write_i32::<NetworkEndian>(lower_bound)?;