diff --git a/CMakeScripts/DefineDependsandFlags.cmake b/CMakeScripts/DefineDependsandFlags.cmake
index 8f38d37fd51470887538d94e882bcdf35805b8ef..93189edf5643f610e9d861619d4b4f0320bd6b6a 100644
--- a/CMakeScripts/DefineDependsandFlags.cmake
+++ b/CMakeScripts/DefineDependsandFlags.cmake
@@ -34,6 +34,8 @@ endif()
 list(APPEND INKSCAPE_CXX_FLAGS "-fstack-protector-strong")
 list(APPEND INKSCAPE_CXX_FLAGS "-Werror=format")                # e.g.: printf("%s", std::string("foo"))
 list(APPEND INKSCAPE_CXX_FLAGS "-Werror=format-security")       # e.g.: printf(variable);
+list(APPEND INKSCAPE_CXX_FLAGS "-Werror=ignored-qualifiers")    # e.g.: const int foo();
+list(APPEND INKSCAPE_CXX_FLAGS "-Werror=return-type")           # non-void functions that don't return a value
 list(APPEND INKSCAPE_CXX_FLAGS "-Wno-switch")                   # See !849 for discussion
 list(APPEND INKSCAPE_CXX_FLAGS_DEBUG "-Og")                     # -Og for _FORTIFY_SOURCE. One could add -Weffc++ here to see approx. 6000 warnings
 list(APPEND INKSCAPE_CXX_FLAGS_DEBUG "-Wcomment")
diff --git a/src/live_effects/effect-enum.h b/src/live_effects/effect-enum.h
index 2dc75b0bb71827a962f281259187e3770590ae3a..c72c53a99da0e8ddb296bc2926215dc1cd45971d 100644
--- a/src/live_effects/effect-enum.h
+++ b/src/live_effects/effect-enum.h
@@ -204,7 +204,7 @@ class EnumEffectDataConverter {
         return empty_string;
     }
 
-    const bool get_on_path(const E id) const
+    bool get_on_path(const E id) const
     {
         for (unsigned int i = 0; i < _length; ++i) {
             if (_data[i].id == id)
@@ -214,7 +214,7 @@ class EnumEffectDataConverter {
         return false;
     }
 
-    const bool get_on_shape(const E id) const
+    bool get_on_shape(const E id) const
     {
         for (unsigned int i = 0; i < _length; ++i) {
             if (_data[i].id == id)
@@ -224,7 +224,7 @@ class EnumEffectDataConverter {
         return false;
     }
 
-    const bool get_on_group(const E id) const
+    bool get_on_group(const E id) const
     {
         for (unsigned int i = 0; i < _length; ++i) {
             if (_data[i].id == id)
@@ -234,7 +234,7 @@ class EnumEffectDataConverter {
         return false;
     }
 
-    const bool get_on_image(const E id) const
+    bool get_on_image(const E id) const
     {
         for (unsigned int i = 0; i < _length; ++i) {
             if (_data[i].id == id)
@@ -244,7 +244,7 @@ class EnumEffectDataConverter {
         return false;
     }
 
-    const bool get_on_text(const E id) const
+    bool get_on_text(const E id) const
     {
         for (unsigned int i = 0; i < _length; ++i) {
             if (_data[i].id == id)
@@ -254,7 +254,7 @@ class EnumEffectDataConverter {
         return false;
     }
 
-    const bool get_experimental(const E id) const
+    bool get_experimental(const E id) const
     {
         for (unsigned int i = 0; i < _length; ++i) {
             if (_data[i].id == id)
diff --git a/src/live_effects/parameter/colorpicker.h b/src/live_effects/parameter/colorpicker.h
index ef917b270be404d10391badf7c191f5df1bfbd23..41579eaeb49906bae3af8d4656ddf63598d65074 100644
--- a/src/live_effects/parameter/colorpicker.h
+++ b/src/live_effects/parameter/colorpicker.h
@@ -35,7 +35,7 @@ public:
     
     void param_set_default() override;
 
-    const guint32 get_value() const { return value; };
+    guint32 get_value() const { return value; };
 
 private:
     ColorPickerParam(const ColorPickerParam&) = delete;
diff --git a/src/ui/modifiers.h b/src/ui/modifiers.h
index 457bf934746b63dc7808b2905ea2619f451abf1d..3c31b01edf48b86054b18ad0713b52214592eb90 100644
--- a/src/ui/modifiers.h
+++ b/src/ui/modifiers.h
@@ -127,7 +127,7 @@ public:
     char const * get_id() const { return _id; }
     char const * get_name() const { return _name; }
     char const * get_description() const { return _desc; }
-    const Trigger get_trigger() const { return _category | _trigger; }
+    Trigger get_trigger() const { return _category | _trigger; }
 
     // Set user value
     void set_keys(KeyMask and_mask, KeyMask not_mask) {
@@ -145,12 +145,12 @@ public:
     bool is_set_user() const { return _and_mask_user != NOT_SET; }
 
     // Get value, either user defined value or default
-    const KeyMask get_and_mask() {
+    KeyMask get_and_mask() {
         if(_and_mask_user != NOT_SET) return _and_mask_user;
         if(_and_mask_keys != NOT_SET) return _and_mask_keys;
         return _and_mask_default;
     }
-    const KeyMask get_not_mask() {
+    KeyMask get_not_mask() {
         // The not mask is enabled by the AND mask being set first.
         if(_and_mask_user != NOT_SET) return _not_mask_user;
         if(_and_mask_keys != NOT_SET) return _not_mask_keys;
diff --git a/src/util/const_char_ptr.h b/src/util/const_char_ptr.h
index 872ca6720b01835dcf515164ebf5e7024babbb9a..44e69063f7337fd45f8743e4296f9e198b1eecd5 100644
--- a/src/util/const_char_ptr.h
+++ b/src/util/const_char_ptr.h
@@ -30,7 +30,7 @@ public:
     const_char_ptr(const char* const data) noexcept: m_data(data) {};
     const_char_ptr(const Glib::ustring& str) noexcept: const_char_ptr(str.c_str()) {};
     const_char_ptr(const std::string& str) noexcept: const_char_ptr(str.c_str()) {};
-    const_char_ptr(const ptr_shared& shared) : const_char_ptr(static_cast<const char* const>(shared)) {};
+    const_char_ptr(const ptr_shared& shared) : const_char_ptr(static_cast<const char*>(shared)) {};
 
     const char * data() const noexcept { return m_data; }
 private:
diff --git a/src/xml/attribute-record.h b/src/xml/attribute-record.h
index a763f553ed255be6f294f0c81d821ea0f72cf55d..233016c9f5e2f797454ffbbeaa48a3d9a304de08 100644
--- a/src/xml/attribute-record.h
+++ b/src/xml/attribute-record.h
@@ -40,7 +40,7 @@ class AttributeRecord : public Inkscape::GC::Managed<> {
     GQuark key;
     /** @brief Shared pointer to the value of the attribute */
     Inkscape::Util::ptr_shared value;
-    const bool operator== (const AttributeRecord &o) const {return key==o.key && value==o.value;}
+    bool operator== (const AttributeRecord &o) const {return key==o.key && value==o.value;}
 
     // accept default copy constructor and assignment operator
 };