diff --git a/HISTORY.md b/HISTORY.md
index dc472ef9d..14b58dc3c 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,5 +1,11 @@
 # History
 
+
+## not yet released, version 5.0.2
+
+- Fixed #1136: rocket trajectory example broken (since v4.0.0).
+
+
 ## 2018-07-01, version 5.0.1
 
 - Improved error messaging when converting units. Thanks @gap777.
diff --git a/examples/browser/rocket_trajectory_optimization.html b/examples/browser/rocket_trajectory_optimization.html
index bd2494fb3..4f30cfdd8 100644
--- a/examples/browser/rocket_trajectory_optimization.html
+++ b/examples/browser/rocket_trajectory_optimization.html
@@ -68,9 +68,9 @@
 
     // Define the equations of motion. It is important to maintain the same argument order for each of these functions.
     sim.eval("drdt(r, v, m, phi, gamma) = v sin(gamma)")
-    sim.eval("dvdt(r, v, m, phi, gamma) = -mu / r^2 sin(gamma) + T / m")
+    sim.eval("dvdt(r, v, m, phi, gamma) = -mu / r^2 * sin(gamma) + T / m")
     sim.eval("dmdt(r, v, m, phi, gamma) = -T/g0/isp")
-    sim.eval("dphidt(r, v, m, phi, gamma) = v/r cos(gamma) * rad")
+    sim.eval("dphidt(r, v, m, phi, gamma) = v/r * cos(gamma) * rad")
     sim.eval("dgammadt(r, v, m, phi, gamma) = (1/r * (v - mu / (r v)) * cos(gamma)) * rad")
 
     // Again, remember to maintain the same variable order in the call to ndsolve.