1 files changed, 1 insertions, 1 deletions
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
index 1ad4b249947..b9025eff82c 100644
--- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
@@ -171,7 +171,7 @@ fn write_coverage_mapping<'a>(
     }
 
     let mut virtual_file_mapping = Vec::new();
-    let mut mapping_regions = Vec::new();
+    let mut mapping_regions = Vec::with_capacity(counter_regions.len());
     let mut current_file_name = None;
     let mut current_file_id = 0;