diff --git a/src/librustc_codegen_llvm/back/write.rs b/src/librustc_codegen_llvm/back/write.rs
index 6f6c02618ba1..bfba1c3ecff3 100644
--- a/src/librustc_codegen_llvm/back/write.rs
+++ b/src/librustc_codegen_llvm/back/write.rs
@@ -239,10 +239,7 @@ impl<'a> Drop for DiagnosticHandlers<'a> {
     }
 }
 
-#[allow(improper_ctypes)]
-unsafe extern "C" fn report_inline_asm(cgcx: &CodegenContext<LlvmCodegenBackend>,
-                                       msg: &str,
-                                       cookie: c_uint) {
+fn report_inline_asm(cgcx: &CodegenContext<LlvmCodegenBackend>, msg: &str, cookie: c_uint) {
     cgcx.diag_emitter.inline_asm_error(cookie as u32, msg.to_owned());
 }