diff --git a/AppKit/CPTextView/CPTextContainer.j b/AppKit/CPTextView/CPTextContainer.j
index d343b397a..9d9d54b3c 100644
--- a/AppKit/CPTextView/CPTextContainer.j
+++ b/AppKit/CPTextView/CPTextContainer.j
@@ -193,13 +193,16 @@ CPLineMovesUp = 4;
 
 - (void)textViewFrameChanged:(CPNotification)aNotification
 {
-    var newSize = CGSizeMake(_size.width, _size.height);
+    // As in Cocoa, a tracking container fills the text view inside its text container inset on both sides.
+    var newSize = CGSizeMake(_size.width, _size.height),
+        frameSize = [_textView frame].size,
+        inset = [_textView textContainerInset];
 
     if (_widthTracksTextView)
-        newSize.width = [_textView frame].size.width;
+        newSize.width = MAX(0.0, frameSize.width - 2.0 * inset.width);
 
     if (_heightTracksTextView)
-        newSize.height = [_textView frame].size.height;
+        newSize.height = MAX(0.0, frameSize.height - 2.0 * inset.height);
 
     [self setContainerSize:newSize];
 }
diff --git a/AppKit/CPTextView/CPTextView.j b/AppKit/CPTextView/CPTextView.j
index a39c89288..246c89120 100644
--- a/AppKit/CPTextView/CPTextView.j
+++ b/AppKit/CPTextView/CPTextView.j
@@ -210,6 +210,9 @@ var kDelegateRespondsTo_textShouldBeginEditing
         [self _init];
         [aContainer setTextView:self];
 
+        // Fit a container that tracks the text view's size inside the text container inset.
+        [aContainer textViewFrameChanged:nil];
+
         [self setEditable:YES];
         [self setSelectable:YES];
         [self setRichText:NO];
@@ -812,6 +815,9 @@ var kDelegateRespondsTo_textShouldBeginEditing
 {
     _textContainerInset = aSize;
     [self invalidateTextContainerOrigin];
+
+    // A container that tracks the text view's size must shrink or grow with the new inset.
+    [_textContainer textViewFrameChanged:nil];
 }
 
 - (void)invalidateTextContainerOrigin