diff --git a/src/textprop.c b/src/textprop.c
index fcf3741..0abae13 100644
--- a/src/textprop.c
+++ b/src/textprop.c
@@ -1220,7 +1220,7 @@
     oldproplen = get_text_props(curbuf, lnum, &props, FALSE);
 
     len = STRLEN(newp) + 1;
-    line = alloc((int)(len + (oldproplen + proplen) * sizeof(textprop_T)));
+    line = alloc(len + (oldproplen + proplen) * sizeof(textprop_T));
     if (line == NULL)
 	return;
     mch_memmove(line, newp, len);