diff --git a/webfront/Cargo.toml b/webfront/Cargo.toml
index 8ccc7eb..71c9691 100644
--- a/webfront/Cargo.toml
+++ b/webfront/Cargo.toml
@@ -14,7 +14,7 @@ wee_alloc = "0.4.5"
 sbp = { path = "../sbp", features = ["f32"] }
 ndarray = "0.13.1"
 euler = { path = "../euler" }
-maxwell = { path = "../maxwell", features = ["sparse"] }
+maxwell = { path = "../maxwell" }
 shallow-water = { path = "../shallow_water" }
 console_log = "0.2.0"
 log = "0.4.8"
diff --git a/webfront/frontend/main.js b/webfront/frontend/main.js
index 77e91cc..f70b1ce 100644
--- a/webfront/frontend/main.js
+++ b/webfront/frontend/main.js
@@ -438,8 +438,8 @@ class FieldDrawer {
         draw();
         switch (eq_set) {
             case "maxwell":
-                // universe.advance(0.2*Math.min(1/width, 1/height));
-                universe.advance_with_matrix(0.2*Math.min(1/width, 1/height));
+                universe.advance(0.2*Math.min(1/width, 1/height));
+                // universe.advance_with_matrix(0.2*Math.min(1/width, 1/height));
                 break;
             case "euler":
                 universe.advance_upwind(0.2*Math.min(1/width, 1/height));
diff --git a/webfront/src/maxwell.rs b/webfront/src/maxwell.rs
index 5bfe760..4916c56 100644
--- a/webfront/src/maxwell.rs
+++ b/webfront/src/maxwell.rs
@@ -25,6 +25,11 @@ impl MaxwellUniverse {
         self.0.advance_upwind(dt)
     }
 
+    #[cfg(feature = "sparse")]
+    pub fn advance_with_matrix(&mut self, dt: f32) {
+        self.0.advance_sparse(dt)
+    }
+
     pub fn get_ex_ptr(&self) -> *const u8 {
         self.0.field().ex().as_ptr() as *const u8
     }