diff --git a/cmd/symbol_inject/macho.go b/cmd/symbol_inject/macho.go
index 0945293..6a1de99 100644
--- a/cmd/symbol_inject/macho.go
+++ b/cmd/symbol_inject/macho.go
@@ -26,7 +26,7 @@
 		return maxUint64, maxUint64, cantParseError{err}
 	}
 
-	// TODO(ccross): why?
+	// symbols in macho files seem to be prefixed with an underscore
 	symbolName = "_" + symbolName
 
 	for i, symbol := range machoFile.Symtab.Syms {