diff --git a/mul.nim b/mul.nim
index c7f1246..1c14b84 100644
--- a/mul.nim
+++ b/mul.nim
@@ -2,7 +2,7 @@ import cligen, sequtils
 import common
 
 proc main(integers:seq[int]) =
-    if integers > 0:
+    if integers.len > 0:
         echo integers.foldl(a * b)
 
 dispatch(main, version=("version", nimbaseVersion))
diff --git a/sub.nim b/sub.nim
index 6f4a29d..50b9a5e 100644
--- a/sub.nim
+++ b/sub.nim
@@ -2,7 +2,7 @@ import cligen, sequtils
 import common
 
 proc main(integers:seq[int]) =
-    if integers > 0:
+    if integers.len > 0:
         echo integers.foldl(a - b)
 
 dispatch(main, version=("version", nimbaseVersion))