diff --git a/CMakeLists.txt b/CMakeLists.txt
index abb86a108..7b7c797d9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -538,6 +538,10 @@ pkg_check_modules(LCMS REQUIRED lcms2>=2.6)
 pkg_check_modules(EXPAT REQUIRED expat>=2.1)
 pkg_check_modules(FFTW3F REQUIRED fftw3f)
 
+# By default little-cms2 uses 'register' keyword which is deprecated and removed in c++17
+# This definition forces not to use it
+add_definitions("-DCMS_NO_REGISTER_KEYWORD")
+
 #Set the appropriate FFTW flags on macOS
 if(APPLE AND OPTION_OMP)
         set(EXTRA_LIB "-L${LOCAL_PREFIX}/lib -lfftw3f_omp -lfftw3f -lm")
diff --git a/rtengine/dfmanager.cc b/rtengine/dfmanager.cc
index 52de10339..5ad664b52 100644
--- a/rtengine/dfmanager.cc
+++ b/rtengine/dfmanager.cc
@@ -317,7 +317,6 @@ private:
     typedef std::map<std::string, std::vector<badPix> > bpList_t;
     dfList_t dfList;
     bpList_t bpList;
-    bool initialized;
     Glib::ustring currentPath;
     dfInfo* addFileInfo(const Glib::ustring &filename, bool pool = true);
     dfInfo* find(const std::string &mak, const std::string &mod, int isospeed, double shut, time_t t);
diff --git a/rtengine/rawimagesource.cc b/rtengine/rawimagesource.cc
index 738ba4e71..2f738f338 100644
--- a/rtengine/rawimagesource.cc
+++ b/rtengine/rawimagesource.cc
@@ -5307,8 +5307,8 @@ void RawImageSource::ItcWB(bool extra, double &tempref, double &greenref, double
         Glib::ustring profuse;
         profuse = "JDCmax";
 
-        int limx = 0.05f;
-        int limy = 0.04f;
+        float limx = 0.05f;
+        float limy = 0.04f;
 
         if (wbpar.itcwb_prim == "srgb") {
             profuse = "sRGB";
diff --git a/rtgui/dirbrowser.cc b/rtgui/dirbrowser.cc
index 7f5a4c3e3..925fdc606 100644
--- a/rtgui/dirbrowser.cc
+++ b/rtgui/dirbrowser.cc
@@ -393,7 +393,9 @@ Gtk::TreePath DirBrowser::expandToDir (const Glib::ustring& absDirPath)
 
     char* dcpy = strdup (absDirPath.c_str());
     char* dir = strtok (dcpy, "/\\");
+#ifdef _WIN32
     int count = 0;
+#endif
     expandSuccess = true;
 
 #ifndef _WIN32
@@ -436,8 +438,9 @@ Gtk::TreePath DirBrowser::expandToDir (const Glib::ustring& absDirPath)
             ++ix;
             ++i;
         }
-
+#ifdef _WIN32
         count++;
+#endif
         dir = strtok(nullptr, "/\\");
     }
 
diff --git a/rtgui/editwindow.h b/rtgui/editwindow.h
index a5932c081..02b7cd23b 100644
--- a/rtgui/editwindow.h
+++ b/rtgui/editwindow.h
@@ -24,7 +24,7 @@
 #include "guiutils.h"
 
 class EditorPanel;
-class ExternalEditor;
+struct ExternalEditor;
 class RTWindow;
 
 class EditWindow :
diff --git a/rtgui/flatfield.cc b/rtgui/flatfield.cc
index 21cdb4315..5246381c3 100644
--- a/rtgui/flatfield.cc
+++ b/rtgui/flatfield.cc
@@ -445,7 +445,7 @@ void FlatField::setGainMap(bool enabled) {
     flatFieldFromMetaData->set_sensitive(enabled);
     if (!enabled) {
         idle_register.add(
-            [this, enabled]() -> bool
+            [this]() -> bool
             {
                 disableListener();
                 flatFieldFromMetaData->setValue(false);
diff --git a/rtgui/lockablecolorpicker.h b/rtgui/lockablecolorpicker.h
index b18a56028..3de6256e9 100644
--- a/rtgui/lockablecolorpicker.h
+++ b/rtgui/lockablecolorpicker.h
@@ -30,7 +30,7 @@ namespace rtengine
 namespace procparams
 {
 
-class ColorManagementParams;
+struct ColorManagementParams;
 
 }
 
diff --git a/rtgui/pointermotionlistener.h b/rtgui/pointermotionlistener.h
index f9fda419c..2f19ae0b9 100644
--- a/rtgui/pointermotionlistener.h
+++ b/rtgui/pointermotionlistener.h
@@ -28,7 +28,7 @@ namespace rtengine
 namespace procparams
 {
 
-class ColorManagementParams;
+struct ColorManagementParams;
 
 }