diff --git a/Cargo.toml b/Cargo.toml
index d693e14..2cec4a7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -73,7 +73,7 @@ proptest = ["dep:proptest"]
 rand = ["dep:rand"]
 rkyv = ["dep:rkyv"]
 rkyv-safe = ["rkyv/validation"]
-rocket-traits = ["dep:rocket"]
+rocket-traits = ["dep:rocket", "std"]
 rust-fuzz = ["dep:arbitrary"]
 serde = ["dep:serde"]
 serde-arbitrary-precision = ["serde-with-arbitrary-precision"]
diff --git a/src/decimal.rs b/src/decimal.rs
index 5df67f3..e34fbea 100644
--- a/src/decimal.rs
+++ b/src/decimal.rs
@@ -573,7 +573,7 @@ impl Decimal {
     pub fn from_scientific(value: &str) -> Result<Decimal, Error> {
         const ERROR_MESSAGE: &str = "Failed to parse";
 
-        let mut split = value.splitn(2, |c| c == 'e' || c == 'E');
+        let mut split = value.splitn(2, ['e', 'E']);
 
         let base = split.next().ok_or_else(|| Error::from(ERROR_MESSAGE))?;
         let exp = split.next().ok_or_else(|| Error::from(ERROR_MESSAGE))?;
diff --git a/src/serde.rs b/src/serde.rs
index c18e08e..ea19e89 100644
--- a/src/serde.rs
+++ b/src/serde.rs
@@ -370,8 +370,10 @@ impl<'de> serde::de::Visitor<'de> for DecimalVisitor {
     }
 }
 
+#[cfg(any(feature = "serde-with-float", feature = "serde-with-arbitrary-precision"))]
 struct OptionDecimalVisitor;
 
+#[cfg(any(feature = "serde-with-float", feature = "serde-with-arbitrary-precision"))]
 impl<'de> serde::de::Visitor<'de> for OptionDecimalVisitor {
     type Value = Option<Decimal>;