diff --git a/src/engine/math_util.c b/src/engine/math_util.c
index 722d12466..c410e558b 100644
--- a/src/engine/math_util.c
+++ b/src/engine/math_util.c
@@ -1339,8 +1339,8 @@ s32 ray_surface_intersect(Vec3f orig, Vec3f dir, f32 dir_length, struct Surface
     vec3f_cross(h, dir, e2);
     // Determine the cos(angle) difference between ray and surface normals.
     f32 det = vec3f_dot(e1, h);
-    // Check if we're perpendicular from the surface.
-    if ((det > -NEAR_ZERO) && (det < NEAR_ZERO)) return FALSE;
+    // Check if we're perpendicular or pointing away from the surface.
+    if (det < NEAR_ZERO) return FALSE;
     // Check if we're making contact with the surface.
     // Make f the inverse of the cos(angle) between ray and surface normals.
     f32 f = 1.0f / det; // invDet