diff --git a/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
index 38fcd0527da..87906dee4d3 100644
--- a/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
@@ -121,7 +121,7 @@ extern "C" void LLVMRustCoverageWriteMappingToBuffer(
     unsigned NumVirtualFileMappingIDs,
     const LLVMRustCounterExpression *RustExpressions,
     unsigned NumExpressions,
-    LLVMRustCounterMappingRegion *RustMappingRegions,
+    const LLVMRustCounterMappingRegion *RustMappingRegions,
     unsigned NumMappingRegions,
     RustStringRef BufferOut) {
   // Convert from FFI representation to LLVM representation.