diff --git a/src/grid/mod.rs b/src/grid/mod.rs
index 0eea4201..9b36fcdf 100644
--- a/src/grid/mod.rs
+++ b/src/grid/mod.rs
@@ -244,7 +244,7 @@ impl<T: Copy + Clone> Grid<T> {
     }
 
     fn grow_cols(&mut self, cols: index::Column, template: &T) {
-        for row in self.raw.iter_mut() {
+        for row in self.raw.iter_mut_raw() {
             row.grow(cols, template);
         }
 
diff --git a/src/grid/storage.rs b/src/grid/storage.rs
index cadd4e29..e7c1a307 100644
--- a/src/grid/storage.rs
+++ b/src/grid/storage.rs
@@ -12,6 +12,7 @@
 /// implementation is provided. Anything from Vec that should be exposed must be
 /// done so manually.
 use std::ops::{Index, IndexMut};
+use std::slice;
 
 use index::Line;
 
@@ -183,10 +184,25 @@ impl<T> Storage<T> {
         self.inner.swap(a, b);
     }
 
+    /// Iterator over *logical* entries in the storage
+    ///
+    /// This *does not* iterate over hidden entries.
     pub fn iter_mut(&mut self) -> IterMut<T> {
         IterMut { storage: self, index: 0 }
     }
 
+    /// Iterate over *all* entries in the underlying buffer
+    ///
+    /// This includes hidden entries.
+    ///
+    /// XXX This suggests that Storage is a leaky abstraction. Ultimately, this
+    ///     is needed because of the grow lines functionality implemented on
+    ///     this type, and maybe that's where the leak is necessitating this
+    ///     accessor.
+    pub fn iter_mut_raw<'a>(&'a mut self) -> slice::IterMut<'a, T> {
+        self.inner.iter_mut()
+    }
+
     pub fn rotate(&mut self, count: isize) {
         debug_assert!(count.abs() as usize <= self.inner.len());