diff --git a/src/forces.zig b/src/forces.zig
index 86171ea..ca3ee49 100644
--- a/src/forces.zig
+++ b/src/forces.zig
@@ -34,9 +34,9 @@ pub fn drag(
     velocity: vec3.Vec3F64,
 ) vec3.Vec3F64 {
     return .init(
-        velocity.x() * drag_coefficient,
-        velocity.y() * drag_coefficient,
-        velocity.z() * drag_coefficient,
+        -velocity.x() * drag_coefficient,
+        -velocity.y() * drag_coefficient,
+        -velocity.z() * drag_coefficient,
     );
 }
 
@@ -73,7 +73,7 @@ test "drag is correct" {
     const velocity = vec3.Vec3F64.init(0, 1, 1);
     const f_drag = drag(0.5, velocity);
 
-    try std.testing.expectApproxEqAbs(0, f_drag.x(), 1e-11);
-    try std.testing.expectApproxEqAbs(0.5, f_drag.y(), 1e-11);
-    try std.testing.expectApproxEqAbs(0.5, f_drag.z(), 1e-11);
+    try std.testing.expectApproxEqAbs(-0.0, f_drag.x(), 1e-11);
+    try std.testing.expectApproxEqAbs(-0.5, f_drag.y(), 1e-11);
+    try std.testing.expectApproxEqAbs(-0.5, f_drag.z(), 1e-11);
 }
diff --git a/src/integration.zig b/src/integration.zig
index 1e7578c..b6d53cd 100644
--- a/src/integration.zig
+++ b/src/integration.zig
@@ -28,14 +28,14 @@ pub fn timestep(dt: f64, d: drone.Drone, props: []const drone.Propeller, s: *dro
     );
 
     s.omega = vec3.vec3Add(s.omega, vec3.vec3Scale(omega_dot, dt));
-    const half_omege_quat: vec3.QuatF64 = .init(
+    const half_omega_quat: vec3.QuatF64 = .init(
         s.omega.x() * 0.5,
         s.omega.y() * 0.5,
         s.omega.z() * 0.5,
         0,
     );
 
-    const qdot = vec3.quatMul(half_omege_quat, s.q);
+    const qdot = vec3.quatMul(half_omega_quat, s.q);
     s.q = vec3.quatAdd(s.q, vec3.quatScale(qdot, dt)).normalized();
     return;
 }
@@ -85,4 +85,23 @@ test "Validate timesteps" {
     try std.testing.expectApproxEqAbs(0.12403234937465502, state.q.y(), 1e-12);
     try std.testing.expectApproxEqAbs(0.006201617468732751, state.q.z(), 1e-11);
     try std.testing.expectApproxEqAbs(0.9922587949972401, state.q.w(), 1e-11);
+
+    timestep(0.005, d, &props, &state);
+
+    try std.testing.expectApproxEqAbs(-1.23072190e+01, state.v.x(), 1e-7);
+    try std.testing.expectApproxEqAbs(-7.69201185e-02, state.v.y(), 1e-8);
+    try std.testing.expectApproxEqAbs(-9.83635311e+01, state.v.z(), 1e-7);
+
+    try std.testing.expectApproxEqAbs(-6.15360950e-02, state.x_cg.x(), 1e-9);
+    try std.testing.expectApproxEqAbs(-3.84600592e-04, state.x_cg.y(), 1e-9);
+    try std.testing.expectApproxEqAbs(-7.41572489e-01, state.x_cg.z(), 1e-9);
+
+    try std.testing.expectApproxEqAbs(-0.46875, state.omega.x(), 1e-12);
+    try std.testing.expectApproxEqAbs(100, state.omega.y(), 1e-12);
+    try std.testing.expectApproxEqAbs(5, state.omega.z(), 1e-11);
+
+    try std.testing.expectApproxEqAbs(-0.0011280012096230429, state.q.x(), 1e-12);
+    try std.testing.expectApproxEqAbs(0.36096743708693396, state.q.y(), 1e-12);
+    try std.testing.expectApproxEqAbs(0.01790701920276581, state.q.z(), 1e-12);
+    try std.testing.expectApproxEqAbs(0.9324057998744074, state.q.w(), 1e-12);
 }