diff --git a/gcc/rust/expand/rust-proc-macro.cc b/gcc/rust/expand/rust-proc-macro.cc
index acd7f711a28..7843ead4412 100644
--- a/gcc/rust/expand/rust-proc-macro.cc
+++ b/gcc/rust/expand/rust-proc-macro.cc
@@ -26,7 +26,7 @@ namespace Rust {
 
 const std::string PROC_MACRO_DECL_PREFIX = "__gccrs_proc_macro_decls_";
 
-ProcMacro::TokenStream
+static ProcMacro::TokenStream
 tokenstream_from_string (std::string &data, bool &lex_error)
 {
   // FIXME: Insert location pointing to call site in tokens
@@ -92,7 +92,7 @@ load_macros_array (std::string path)
       return nullptr;
     }
 
-  if (!REGISTER_CALLBACK (handle, __gccrs_pm_callback_from_str_fn,
+  if (!REGISTER_CALLBACK (handle, __gccrs_proc_macro_from_str_fn,
 			  tokenstream_from_string))
     return nullptr;
 
diff --git a/libgrust/libproc_macro/proc_macro.cc b/libgrust/libproc_macro/proc_macro.cc
index effe7178b89..a4046919721 100644
--- a/libgrust/libproc_macro/proc_macro.cc
+++ b/libgrust/libproc_macro/proc_macro.cc
@@ -51,4 +51,4 @@ Procmacro::make_bang (const char *name, BangMacro macro)
 
 } // namespace ProcMacro
 
-ProcMacro::from_str_function_t __gccrs_pm_callback_from_str_fn = nullptr;
+ProcMacro::from_str_function_t __gccrs_proc_macro_from_str_fn = nullptr;
diff --git a/libgrust/libproc_macro/registration.h b/libgrust/libproc_macro/registration.h
index bba69b1e9bc..5cefc37de11 100644
--- a/libgrust/libproc_macro/registration.h
+++ b/libgrust/libproc_macro/registration.h
@@ -32,6 +32,6 @@ using from_str_function_t = ProcMacro::TokenStream (*) (std::string &, bool &);
 
 } // namespace ProcMacro
 
-extern "C" ProcMacro::from_str_function_t __gccrs_pm_callback_from_str_fn;
+extern "C" ProcMacro::from_str_function_t __gccrs_proc_macro_from_str_fn;
 
 #endif /* !REGISTRATION_H */
diff --git a/libgrust/libproc_macro/tokenstream.cc b/libgrust/libproc_macro/tokenstream.cc
index 5d9abb69a2d..0f7f1f2079b 100644
--- a/libgrust/libproc_macro/tokenstream.cc
+++ b/libgrust/libproc_macro/tokenstream.cc
@@ -49,7 +49,7 @@ TokenStream::make_tokenstream (std::uint64_t capacity)
 TokenStream
 TokenStream::make_tokenstream (std::string &source, bool &has_error)
 {
-  return __gccrs_pm_callback_from_str_fn (source, has_error);
+  return __gccrs_proc_macro_from_str_fn (source, has_error);
 }
 
 void