diff --git a/src/types/list.rs b/src/types/list.rs
index 53cac952..34122adc 100644
--- a/src/types/list.rs
+++ b/src/types/list.rs
@@ -776,6 +776,8 @@ mod tests {
 
     use std::ops::Range;
 
+    // An iterator that lies about its `ExactSizeIterator` implementation.
+    // See https://github.com/PyO3/pyo3/issues/2118
     struct FaultyIter(Range<usize>, usize);
 
     impl Iterator for FaultyIter {
diff --git a/src/types/tuple.rs b/src/types/tuple.rs
index b40c0d5c..95c568d2 100644
--- a/src/types/tuple.rs
+++ b/src/types/tuple.rs
@@ -758,7 +758,9 @@ mod tests {
     }
 
     use std::ops::Range;
-
+    
+    // An iterator that lies about its `ExactSizeIterator` implementation.
+    // See https://github.com/PyO3/pyo3/issues/2118
     struct FaultyIter(Range<usize>, usize);
 
     impl Iterator for FaultyIter {