diff --git a/include/light/bounce.hh b/include/light/bounce.hh
index 4ddc0be1..49d84be8 100644
--- a/include/light/bounce.hh
+++ b/include/light/bounce.hh
@@ -44,7 +44,7 @@ typedef struct {
 // public functions
 
 const std::vector<bouncelight_t> &BounceLights();
-std::vector<bouncelight_t> BounceLightsForFaceNum(int facenum);
+const std::vector<bouncelight_t> &BounceLightsForFaceNum(int facenum);
 void MakeTextureColors (const bsp2_t *bsp);
 void MakeBounceLights (const globalconfig_t &cfg, const bsp2_t *bsp);
 /** Returns color components in [0, 255] */
diff --git a/light/bounce.cc b/light/bounce.cc
index 2ca8138b..ae2104c2 100644
--- a/light/bounce.cc
+++ b/light/bounce.cc
@@ -261,13 +261,15 @@ const std::vector<bouncelight_t> &BounceLights()
     return radlights;
 }
 
-std::vector<bouncelight_t> BounceLightsForFaceNum(int facenum)
+const std::vector<bouncelight_t> &BounceLightsForFaceNum(int facenum)
 {
     const auto &vec = radlightsByFacenum.find(facenum);
     if (vec != radlightsByFacenum.end()) {
         return vec->second;
     }
-    return {};
+    
+    static std::vector<bouncelight_t> empty;
+    return empty;
 }
 
 glm::vec3 Palette_GetColor(int i)
diff --git a/light/ltface.cc b/light/ltface.cc
index 32bed96a..b3bd39f1 100644
--- a/light/ltface.cc
+++ b/light/ltface.cc
@@ -1644,7 +1644,7 @@ LightFace_BounceLightsDebug(const lightsurf_t *lightsurf, lightmapdict_t *lightm
     // reset all lightmaps to black (lazily)
     Lightmap_ClearAll(lightmaps);
     
-    std::vector<bouncelight_t> vpls = BounceLightsForFaceNum(Face_GetNum(lightsurf->bsp, lightsurf->face));
+    const std::vector<bouncelight_t> &vpls = BounceLightsForFaceNum(Face_GetNum(lightsurf->bsp, lightsurf->face));
     if (vpls.size()) {
         Q_assert(vpls.size() == 1); // for now only 1 vpl per face