diff --git a/include/light/ltface.hh b/include/light/ltface.hh
index 345ae732..50f8cd81 100644
--- a/include/light/ltface.hh
+++ b/include/light/ltface.hh
@@ -65,6 +65,8 @@ struct lightgrid_sample_t {
 
     qvec3b round_to_int() const;
     float brightness() const;
+
+    bool operator==(const lightgrid_sample_t &other) const;
 };
 
 struct lightgrid_samples_t {
@@ -72,6 +74,8 @@ struct lightgrid_samples_t {
 
     void add(const qvec3d &color, int style);
     int used_styles() const;
+
+    bool operator==(const lightgrid_samples_t &other) const;
 };
 
 lightgrid_samples_t CalcLightgridAtPoint(const mbsp_t *bsp, const qvec3d &world_point);
diff --git a/light/ltface.cc b/light/ltface.cc
index 01e75aab..c422ddb1 100644
--- a/light/ltface.cc
+++ b/light/ltface.cc
@@ -3326,6 +3326,13 @@ float lightgrid_sample_t::brightness() const
     return (color[0] + color[1] + color[2]) / 3.0;
 }
 
+bool lightgrid_sample_t::operator==(const lightgrid_sample_t &other) const
+{
+    return used == other.used &&
+        style == other.style &&
+        color == other.color;
+}
+
 int lightgrid_samples_t::used_styles() const
 {
     int used = 0;
@@ -3339,6 +3346,11 @@ int lightgrid_samples_t::used_styles() const
     return used;
 }
 
+bool lightgrid_samples_t::operator==(const lightgrid_samples_t &other) const
+{
+    return samples_by_style == other.samples_by_style;
+}
+
 lightgrid_samples_t CalcLightgridAtPoint(const mbsp_t *bsp, const qvec3d &world_point)
 {
     // TODO: use more than 1 ray for better performance