diff --git a/compiler/rustc_codegen_ssa/src/back/linker.rs b/compiler/rustc_codegen_ssa/src/back/linker.rs
index 3d77ddc3f84..ce51b2e9531 100644
--- a/compiler/rustc_codegen_ssa/src/back/linker.rs
+++ b/compiler/rustc_codegen_ssa/src/back/linker.rs
@@ -656,7 +656,7 @@ impl<'a> Linker for GccLinker<'a> {
             return;
         }
 
-        // FIXME hide #[no_mangle] symbols for proc-macros
+        // FIXME(#99978) hide #[no_mangle] symbols for proc-macros
 
         let is_windows = self.sess.target.is_like_windows;
         let path = tmpdir.join(if is_windows { "list.def" } else { "list" });
diff --git a/src/test/run-make-fulldeps/symbol-visibility/Makefile b/src/test/run-make-fulldeps/symbol-visibility/Makefile
index b816afa7395..17052ef4e63 100644
--- a/src/test/run-make-fulldeps/symbol-visibility/Makefile
+++ b/src/test/run-make-fulldeps/symbol-visibility/Makefile
@@ -59,7 +59,7 @@ all:
 	[ "$$($(NM) $(TMPDIR)/$(RDYLIB_NAME) | grep -v __imp_ | grep -c public_generic_function_from_rlib)" -eq "0" ]
 
 	# Check that a proc macro exports its public #[no_mangle] functions
-	# FIXME avoid exporting #[no_mangle] symbols for proc macros
+	# FIXME(#99978) avoid exporting #[no_mangle] symbols for proc macros
 	[ "$$($(NM) $(TMPDIR)/$(CDYLIB_NAME) | grep -v __imp_ | grep -c public_c_function_from_cdylib)" -eq "1" ]
 	# Check that a proc macro exports the public #[no_mangle] functions of dependencies
 	[ "$$($(NM) $(TMPDIR)/$(CDYLIB_NAME) | grep -v __imp_ | grep -c public_c_function_from_rlib)" -eq "1" ]
@@ -108,7 +108,7 @@ endif
 	[ "$$($(NM) $(TMPDIR)/$(RDYLIB_NAME) | grep -v __imp_ | grep -c public_generic_function_from_rlib)" -eq "1" ]
 
 	# Check that a proc macro exports its public #[no_mangle] functions
-	# FIXME avoid exporting #[no_mangle] symbols for proc macros
+	# FIXME(#99978) avoid exporting #[no_mangle] symbols for proc macros
 	[ "$$($(NM) $(TMPDIR)/$(CDYLIB_NAME) | grep -v __imp_ | grep -c public_c_function_from_cdylib)" -eq "1" ]
 	# Check that a proc macro exports the public #[no_mangle] functions of dependencies
 	[ "$$($(NM) $(TMPDIR)/$(CDYLIB_NAME) | grep -v __imp_ | grep -c public_c_function_from_rlib)" -eq "1" ]