diff --git a/src/strings.c b/src/strings.c
index 9b66ee0..6b2ff0a 100644
--- a/src/strings.c
+++ b/src/strings.c
@@ -269,12 +269,12 @@
 		*d++ = *p++;
 		continue;
 	    }
-	    if (do_special && find_cmdline_var(p, &l) >= 0 && l > 0)
+	    if (do_special && find_cmdline_var(p, &l) >= 0)
 	    {
 		*d++ = '\\';		// insert backslash
-		do			// copy the var
-		    *d++ = *p++;
-		while (--l > 0);
+		memcpy(d, p, l);	// copy the var
+		d += l;
+		p += l;
 		continue;
 	    }
 	    if (*p == '\\' && fish_like)