diff --git a/cmake/ToLua.cmake b/cmake/ToLua.cmake
index 823f8f58..b5c6d153 100644
--- a/cmake/ToLua.cmake
+++ b/cmake/ToLua.cmake
@@ -24,20 +24,20 @@ function(wrap_tolua VAR FIL)
 
   get_filename_component(ABS_FIL ${FIL} ABSOLUTE)
   get_filename_component(FIL_WE ${FIL} NAME_WE)
-  list(APPEND ${VAR} "${CMAKE_CURRENT_BINARY_DIR}/lib${FIL_WE}.c")
+  list(APPEND ${VAR} "${CMAKE_CURRENT_BINARY_DIR}/lib${FIL_WE}.cc")
 
   if(DEFINED ARGV2)
     get_filename_component(PATCH ${ARGV2} ABSOLUTE)
-    set(TOLUA_OUT ${CMAKE_CURRENT_BINARY_DIR}/lib${FIL_WE}-orig.c)
-    add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/lib${FIL_WE}.c
+    set(TOLUA_OUT ${CMAKE_CURRENT_BINARY_DIR}/lib${FIL_WE}-orig.cc)
+    add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/lib${FIL_WE}.cc
       COMMAND ${APP_PATCH} -s ${TOLUA_OUT} ${PATCH} -o
-      ${CMAKE_CURRENT_BINARY_DIR}/lib${FIL_WE}.c
+      ${CMAKE_CURRENT_BINARY_DIR}/lib${FIL_WE}.cc
       DEPENDS ${TOLUA_OUT} ${PATCH}
-      COMMENT "Patching lib${FIL_WE}-orig.c"
+      COMMENT "Patching lib${FIL_WE}-orig.cc"
       VERBATIM)
     set_source_files_properties(${TOLUA_OUT} PROPERTIES GENERATED TRUE)
   else()
-    set(TOLUA_OUT ${CMAKE_CURRENT_BINARY_DIR}/lib${FIL_WE}.c)
+    set(TOLUA_OUT ${CMAKE_CURRENT_BINARY_DIR}/lib${FIL_WE}.cc)
   endif(DEFINED ARGV2)
 
   # Call toluapp from 3rdparty/ path directly. The last argument to toluapp is
@@ -54,7 +54,7 @@ function(wrap_tolua VAR FIL)
     ${${VAR}}
     PROPERTIES
     COMPILE_FLAGS
-    "-Wno-bad-function-cast -Wno-unused-parameter -Wno-cast-qual -Wno-error=pedantic"
+    "-Wno-unused-parameter -Wno-cast-qual -Wno-error=pedantic"
   )
 
   set(${VAR} ${${VAR}} PARENT_SCOPE)
diff --git a/lua/libcairo-helper.h b/lua/libcairo-helper.h
index 6c7c1a0e..2e48c0ae 100644
--- a/lua/libcairo-helper.h
+++ b/lua/libcairo-helper.h
@@ -26,17 +26,18 @@
 #define _LIBCAIRO_HELPER_H_
 
 #include <cairo.h>
+#include <cstdlib>
 
 cairo_text_extents_t *create_cairo_text_extents_t(void) {
-  return calloc(1, sizeof(cairo_text_extents_t));
+  return (cairo_text_extents_t *)calloc(1, sizeof(cairo_text_extents_t));
 }
 
 cairo_font_extents_t *create_cairo_font_extents_t(void) {
-  return calloc(1, sizeof(cairo_font_extents_t));
+  return (cairo_font_extents_t *)calloc(1, sizeof(cairo_font_extents_t));
 }
 
 cairo_matrix_t *create_cairo_matrix_t(void) {
-  return calloc(1, sizeof(cairo_matrix_t));
+  return (cairo_matrix_t *)calloc(1, sizeof(cairo_matrix_t));
 }
 
 void destroy_cairo_text_extents_t(cairo_text_extents_t *pointer) {
diff --git a/lua/libcairo_imlib2_helper.h b/lua/libcairo_imlib2_helper.h
index 3b5718a0..a1b39ba2 100644
--- a/lua/libcairo_imlib2_helper.h
+++ b/lua/libcairo_imlib2_helper.h
@@ -36,7 +36,7 @@ void cairo_draw_image(const char *file, cairo_surface_t *cs, int x, int y,
   Imlib_Image premul;
   cairo_surface_t *result;
   cairo_t *cr;
-  Imlib_Image *image = imlib_load_image(file);
+  auto image = imlib_load_image(file);
   if (!image) { return; }
 
   imlib_context_set_image(image);
@@ -64,8 +64,8 @@ void cairo_draw_image(const char *file, cairo_surface_t *cs, int x, int y,
 
   /* now pass the result to cairo */
   result = cairo_image_surface_create_for_data(
-      (void *)imlib_image_get_data_for_reading_only(), CAIRO_FORMAT_ARGB32,
-      scaled_w, scaled_h, sizeof(DATA32) * scaled_w);
+      (unsigned char *)imlib_image_get_data_for_reading_only(),
+      CAIRO_FORMAT_ARGB32, scaled_w, scaled_h, sizeof(DATA32) * scaled_w);
 
   cr = cairo_create(cs);
   cairo_set_source_surface(cr, result, x, y);
diff --git a/lua/librsvg-helper.h b/lua/librsvg-helper.h
index 3c94528c..b09e0410 100644
--- a/lua/librsvg-helper.h
+++ b/lua/librsvg-helper.h
@@ -93,7 +93,7 @@ int rsvg_destroy_handle(RsvgHandle *handle) {
 }
 
 RsvgRectangle *rsvg_rectangle_create(void) {
-  return calloc(1, sizeof(RsvgRectangle));
+  return (RsvgRectangle *)calloc(1, sizeof(RsvgRectangle));
 }
 
 void rsvg_rectangle_destroy(RsvgRectangle *rect) { free(rect); }