diff --git a/src/courseware/course/sequence/Unit.jsx b/src/courseware/course/sequence/Unit.jsx
index dc47eb11..0c3dbe94 100644
--- a/src/courseware/course/sequence/Unit.jsx
+++ b/src/courseware/course/sequence/Unit.jsx
@@ -174,7 +174,7 @@ function Unit({
                     src={modalOptions.url}
                     style={{
                       width: '100%',
-                      height: '100%',
+                      height: '100vh',
                     }}
                   />
                 )}