diff --git a/Cargo.toml b/Cargo.toml
index 1ef39370..0d3d59fd 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -790,6 +790,7 @@ rest_pat_in_fully_bound_structs = "warn"
 semicolon_outside_block = "warn"
 str_to_string = "warn"
 string_lit_chars_any = "warn"
+string_slice = "warn"
 string_to_string = "warn"
 suspicious_xor_used_as_pow = "warn"
 tests_outside_test_module = "warn"
diff --git a/src/core/config/proxy.rs b/src/core/config/proxy.rs
index d823e5e4..48f883c6 100644
--- a/src/core/config/proxy.rs
+++ b/src/core/config/proxy.rs
@@ -127,6 +127,7 @@ impl WildCardedDomain {
 impl std::str::FromStr for WildCardedDomain {
 	type Err = std::convert::Infallible;
 
+	#[allow(clippy::string_slice)]
 	fn from_str(s: &str) -> Result<Self, Self::Err> {
 		// maybe do some domain validation?
 		Ok(if s.starts_with("*.") {
diff --git a/src/core/utils/html.rs b/src/core/utils/html.rs
index 938e50ec..fe07b2dd 100644
--- a/src/core/utils/html.rs
+++ b/src/core/utils/html.rs
@@ -6,6 +6,7 @@ pub struct Escape<'a>(pub &'a str);
 
 /// Copied from librustdoc:
 /// * <https://github.com/rust-lang/rust/blob/cbaeec14f90b59a91a6b0f17fc046c66fa811892/src/librustdoc/html/escape.rs>
+#[allow(clippy::string_slice)]
 impl fmt::Display for Escape<'_> {
 	fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
 		// Because the internet is always right, turns out there's not that many
diff --git a/src/core/utils/string.rs b/src/core/utils/string.rs
index 1f2a6572..ec423d53 100644
--- a/src/core/utils/string.rs
+++ b/src/core/utils/string.rs
@@ -9,12 +9,13 @@ pub const EMPTY: &str = "";
 /// common_prefix(&input) == "con";
 /// ```
 #[must_use]
+#[allow(clippy::string_slice)]
 pub fn common_prefix<'a>(choice: &'a [&str]) -> &'a str {
 	choice.first().map_or(EMPTY, move |best| {
 		choice.iter().skip(1).fold(*best, |best, choice| {
 			&best[0..choice
-				.chars()
-				.zip(best.chars())
+				.char_indices()
+				.zip(best.char_indices())
 				.take_while(|&(a, b)| a == b)
 				.count()]
 		})
diff --git a/src/service/sending/resolve.rs b/src/service/sending/resolve.rs
index 77311006..d38509ba 100644
--- a/src/service/sending/resolve.rs
+++ b/src/service/sending/resolve.rs
@@ -484,6 +484,7 @@ impl FedDest {
 	}
 
 	#[inline]
+	#[allow(clippy::string_slice)]
 	fn port(&self) -> Option<u16> {
 		match &self {
 			Self::Literal(addr) => Some(addr.port()),