diff --git a/modules/TODO b/modules/TODO
index 4d56dd94..7920f7f6 100644
--- a/modules/TODO
+++ b/modules/TODO
@@ -1,9 +1,5 @@
 # Modules we still need to use in 2020
 
-# task: find out efficiently if array of unsigned chars is all 0s
-#       - cast to uint64_t, use XOR, go in multiplies of sizeof (uint64_t)
-#	  until the end, check the rest of bytes
-
 # When bit operations are introduced, use src/cast-intptr.c as it uses ^
 
 # Before using this, add the C99 specification paragraph number that allows