diff --git a/crates/hir-def/src/hir/format_args.rs b/crates/hir-def/src/hir/format_args.rs
index dc09b0ef3e..22864b3289 100644
--- a/crates/hir-def/src/hir/format_args.rs
+++ b/crates/hir-def/src/hir/format_args.rs
@@ -178,9 +178,9 @@ pub(crate) fn parse(
     let text = s.text_without_quotes();
     let str_style = match s.quote_offsets() {
         Some(offsets) => {
-            let raw = u32::from(offsets.quotes.0.len()) - 1;
+            let raw = usize::from(offsets.quotes.0.len()) - 1;
             // subtract 1 for the `r` prefix
-            (raw != 0).then(|| raw as usize - 1)
+            (raw != 0).then(|| raw - 1)
         }
         None => None,
     };