diff --git a/rust/proc_macro.go b/rust/proc_macro.go
index 974c096..f8a4bbd 100644
--- a/rust/proc_macro.go
+++ b/rust/proc_macro.go
@@ -33,6 +33,7 @@
 }
 
 type procMacroInterface interface {
+	ProcMacro() bool
 }
 
 var _ compiler = (*procMacroDecorator)(nil)
@@ -90,6 +91,10 @@
 	return rlibAutoDep
 }
 
+func (procMacro *procMacroDecorator) ProcMacro() bool {
+	return true
+}
+
 func (procMacro *procMacroDecorator) everInstallable() bool {
 	// Proc_macros are never installed
 	return false