diff --git a/src/powerset.rs b/src/powerset.rs
index 407c74dfd..914a0e5e0 100644
--- a/src/powerset.rs
+++ b/src/powerset.rs
@@ -51,7 +51,7 @@ impl<I> Iterator for Powerset<I>
 
     fn next(&mut self) -> Option<Vec<I::Item>> {
         if let Some(elt) = self.combs.next() {
-            self.pos += 1;
+            self.pos = self.pos.saturating_add(1);
             Some(elt)
         } else {
             if self.done {
@@ -59,7 +59,7 @@ impl<I> Iterator for Powerset<I>
             } else {
                 self.combs.init(self.combs.k() + 1);
                 if let Some(elt) = self.combs.next() {
-                    self.pos += 1;
+                    self.pos = self.pos.saturating_add(1);
                     Some(elt)
                 } else {
                     // None returned from a new Combinations indicates we're finished.