diff --git a/asm/nasm.c b/asm/nasm.c
index e9cb5c83..8b8982f2 100644
--- a/asm/nasm.c
+++ b/asm/nasm.c
@@ -454,6 +454,7 @@ static char *nasm_quote_filename(const char *fn)
 {
     const unsigned char *p =
         (const unsigned char *)fn;
+    size_t len;
 
     if (!p || !*p)
         return nasm_strdup("\"\"");
@@ -477,7 +478,8 @@ static char *nasm_quote_filename(const char *fn)
     return nasm_strdup(fn);
 
 quote:
-    return nasm_quote(fn, NULL);
+    len = strlen(fn);
+    return nasm_quote(fn, &len);
 }
 
 static void timestamp(void)
diff --git a/asm/preproc.c b/asm/preproc.c
index c72e6368..6a71ad00 100644
--- a/asm/preproc.c
+++ b/asm/preproc.c
@@ -797,7 +797,7 @@ Token *quote_token(Token *t)
  */
 static Token *quote_any_token(Token *t)
 {
-    size_t len;
+    size_t len = t->len;
     char *p;
 
     p = nasm_quote(tok_text(t), &len);