diff --git a/rtengine/rtlensfun.cc b/rtengine/rtlensfun.cc
index 50b3c8a66..4856909f7 100644
--- a/rtengine/rtlensfun.cc
+++ b/rtengine/rtlensfun.cc
@@ -501,7 +501,6 @@ std::unique_ptr<LFModifier> LFDatabase::getModifier(const LFCamera &camera, cons
 
 std::unique_ptr<LFModifier> LFDatabase::findModifier(const LensProfParams &lensProf, const FramesMetaData *idata, int width, int height, const CoarseTransformParams &coarse, int rawRotationDeg)
 {
-    const LFDatabase *db = getInstance();
     Glib::ustring make, model, lens;
     float focallen = idata->getFocalLen();
     if (lensProf.lfAutoMatch()) {
@@ -516,6 +515,11 @@ std::unique_ptr<LFModifier> LFDatabase::findModifier(const LensProfParams &lensP
         model = lensProf.lfCameraModel;
         lens = lensProf.lfLens;
     }
+    if (make.empty() || model.empty() || lens.empty()) {
+        return nullptr;
+    }
+
+    const LFDatabase *db = getInstance();
     LFCamera c = db->findCamera(make, model);
     LFLens l = db->findLens(lensProf.lfAutoMatch() ? c : LFCamera(), lens);
     if (focallen <= 0 && l.data_ && l.data_->MinFocal == l.data_->MaxFocal) {