diff --git a/src/cmd/troff2html/troff2html.c b/src/cmd/troff2html/troff2html.c
index 91145c06..9f43946c 100644
--- a/src/cmd/troff2html/troff2html.c
+++ b/src/cmd/troff2html/troff2html.c
@@ -705,7 +705,7 @@ troffchar(char *s)
 	for(i=0; troffchars[i].name!=nil; i++)
 		if(strcmp(s, troffchars[i].name) == 0)
 			return troffchars[i].value;
-	return s;
+	return strdup(s);
 }
 
 void