diff --git a/rtengine/camconst.cc b/rtengine/camconst.cc
index 6b4a36c4b..469d18571 100644
--- a/rtengine/camconst.cc
+++ b/rtengine/camconst.cc
@@ -184,7 +184,7 @@ CameraConst::parseEntry(void *cJSON_, const char *make_model)
     js = (cJSON *)cJSON_;
 
     CameraConst *cc = new CameraConst;
-    cc->make_model = Glib::ustring(make_model);
+    cc->make_model = make_model;
 
     ji = cJSON_GetObjectItem(js, "dcraw_matrix");
 
@@ -739,7 +739,7 @@ CameraConstantsStore::get(const char make[], const char model[])
     key += " ";
     key += model;
     key = key.uppercase();
-    std::map<Glib::ustring, CameraConst *>::iterator it;
+    std::map<std::string, CameraConst *>::iterator it;
     it = mCameraConstants.find(key);
 
     if (it == mCameraConstants.end()) {
diff --git a/rtengine/camconst.h b/rtengine/camconst.h
index 31b65f3e8..47c8d8bee 100644
--- a/rtengine/camconst.h
+++ b/rtengine/camconst.h
@@ -17,7 +17,7 @@ struct camera_const_levels {
 class CameraConst
 {
 private:
-    Glib::ustring make_model;
+    std::string make_model;
     short dcraw_matrix[12];
     int raw_crop[4];
     int raw_mask[8][4];
@@ -48,7 +48,7 @@ public:
 class CameraConstantsStore
 {
 private:
-    std::map<Glib::ustring, CameraConst *> mCameraConstants;
+    std::map<std::string, CameraConst *> mCameraConstants;
 
     CameraConstantsStore();
     bool parse_camera_constants_file(Glib::ustring filename);