diff --git a/src/openrct2-ui/drawing/engines/HardwareDisplayDrawingEngine.cpp b/src/openrct2-ui/drawing/engines/HardwareDisplayDrawingEngine.cpp
index 36bbd03ca3..ffaf289422 100644
--- a/src/openrct2-ui/drawing/engines/HardwareDisplayDrawingEngine.cpp
+++ b/src/openrct2-ui/drawing/engines/HardwareDisplayDrawingEngine.cpp
@@ -252,7 +252,7 @@ private:
         }
     }
 
-    void CopyBitsToTexture(SDL_Texture * texture, uint8 * src, sint32 width, sint32 height, uint32 * palette)
+    void CopyBitsToTexture(SDL_Texture * texture, uint8 * src, sint32 width, sint32 height, const uint32 * palette)
     {
         void *  pixels;
         sint32     pitch;
diff --git a/src/openrct2-ui/interface/Graph.cpp b/src/openrct2-ui/interface/Graph.cpp
index 6927d22691..4330c0e1cb 100644
--- a/src/openrct2-ui/interface/Graph.cpp
+++ b/src/openrct2-ui/interface/Graph.cpp
@@ -18,7 +18,7 @@
 #include <openrct2/localisation/Localisation.h>
 #include <openrct2-ui/interface/Graph.h>
 
-static void graph_draw_months_uint8(rct_drawpixelinfo *dpi, uint8 *history, sint32 count, sint32 baseX, sint32 baseY)
+static void graph_draw_months_uint8(rct_drawpixelinfo *dpi, const uint8 *history, sint32 count, sint32 baseX, sint32 baseY)
 {
     sint32 i, x, y, yearOver32, currentMonth, currentDay;
 
@@ -42,7 +42,7 @@ static void graph_draw_months_uint8(rct_drawpixelinfo *dpi, uint8 *history, sint
     }
 }
 
-static void graph_draw_line_a_uint8(rct_drawpixelinfo *dpi, uint8 *history, sint32 count, sint32 baseX, sint32 baseY)
+static void graph_draw_line_a_uint8(rct_drawpixelinfo *dpi, const uint8 *history, sint32 count, sint32 baseX, sint32 baseY)
 {
     sint32 i, x, y, lastX, lastY;
     lastX = -1;
@@ -66,7 +66,7 @@ static void graph_draw_line_a_uint8(rct_drawpixelinfo *dpi, uint8 *history, sint
     }
 }
 
-static void graph_draw_line_b_uint8(rct_drawpixelinfo *dpi, uint8 *history, sint32 count, sint32 baseX, sint32 baseY)
+static void graph_draw_line_b_uint8(rct_drawpixelinfo *dpi, const uint8 *history, sint32 count, sint32 baseX, sint32 baseY)
 {
     sint32 i, x, y, lastX, lastY;
 
@@ -96,7 +96,7 @@ void graph_draw_uint8(rct_drawpixelinfo *dpi, uint8 *history, sint32 count, sint
     graph_draw_line_b_uint8(dpi, history, count, baseX, baseY);
 }
 
-static void graph_draw_months_money32(rct_drawpixelinfo *dpi, money32 *history, sint32 count, sint32 baseX, sint32 baseY)
+static void graph_draw_months_money32(rct_drawpixelinfo *dpi, const money32 *history, sint32 count, sint32 baseX, sint32 baseY)
 {
     sint32 i, x, y, yearOver32, currentMonth, currentDay;
 
@@ -120,7 +120,7 @@ static void graph_draw_months_money32(rct_drawpixelinfo *dpi, money32 *history,
     }
 }
 
-static void graph_draw_line_a_money32(rct_drawpixelinfo *dpi, money32 *history, sint32 count, sint32 baseX, sint32 baseY, sint32 modifier, sint32 offset)
+static void graph_draw_line_a_money32(rct_drawpixelinfo *dpi, const money32 *history, sint32 count, sint32 baseX, sint32 baseY, sint32 modifier, sint32 offset)
 {
     sint32 i, x, y, lastX, lastY;
     lastX = -1;
@@ -144,7 +144,7 @@ static void graph_draw_line_a_money32(rct_drawpixelinfo *dpi, money32 *history,
     }
 }
 
-static void graph_draw_line_b_money32(rct_drawpixelinfo *dpi, money32 *history, sint32 count, sint32 baseX, sint32 baseY, sint32 modifier, sint32 offset)
+static void graph_draw_line_b_money32(rct_drawpixelinfo *dpi, const money32 *history, sint32 count, sint32 baseX, sint32 baseY, sint32 modifier, sint32 offset)
 {
     sint32 i, x, y, lastX, lastY;
 
diff --git a/src/openrct2/CmdlineSprite.cpp b/src/openrct2/CmdlineSprite.cpp
index d8ad4d0448..99e9265e77 100644
--- a/src/openrct2/CmdlineSprite.cpp
+++ b/src/openrct2/CmdlineSprite.cpp
@@ -240,7 +240,7 @@ static bool sprite_file_export(sint32 spriteIndex, const char *outPath)
     }
 }
 
-static bool is_transparent_pixel(sint16 *colour){
+static bool is_transparent_pixel(const sint16 *colour){
     return colour[3] < 128;
 }
 
@@ -261,7 +261,7 @@ static bool is_changable_pixel(sint32 palette_index) {
     return true;
 }
 
-static sint32 get_closest_palette_index(sint16 *colour){
+static sint32 get_closest_palette_index(const sint16 *colour){
     uint32 smallest_error = (uint32)-1;
     sint32 best_match = -1;
 
diff --git a/src/openrct2/Game.cpp b/src/openrct2/Game.cpp
index a3a82d5194..f5058f567a 100644
--- a/src/openrct2/Game.cpp
+++ b/src/openrct2/Game.cpp
@@ -737,7 +737,7 @@ sint32 game_do_command_p(uint32 command, sint32 * eax, sint32 * ebx, sint32 * ec
     return MONEY32_UNDEFINED;
 }
 
-void game_log_multiplayer_command(int command, int * eax, int * ebx, int * ecx, int * edx, int * edi, int * ebp)
+void game_log_multiplayer_command(int command, const int * eax, const int * ebx, const int * ecx, int * edx, int * edi, int * ebp)
 {
     // Get player name
     int player_index = network_get_player_index(game_command_playerid);
diff --git a/src/openrct2/Game.h b/src/openrct2/Game.h
index ae205c8f1e..7025e4d67a 100644
--- a/src/openrct2/Game.h
+++ b/src/openrct2/Game.h
@@ -171,7 +171,7 @@ void update_palette_effects();
 sint32 game_do_command(sint32 eax, sint32 ebx, sint32 ecx, sint32 edx, sint32 esi, sint32 edi, sint32 ebp);
 sint32 game_do_command_p(uint32 command, sint32 * eax, sint32 * ebx, sint32 * ecx, sint32 * edx, sint32 * esi, sint32 * edi, sint32 * ebp);
 
-void game_log_multiplayer_command(int command, int * eax, int * ebx, int * ecx, int * edx, int * edi, int * ebp);
+void game_log_multiplayer_command(int command, const int * eax, const int * ebx, const int * ecx, int * edx, int * edi, int * ebp);
 
 void game_load_or_quit_no_save_prompt();
 ParkLoadResult * load_from_sv6(const char * path);
diff --git a/src/openrct2/core/textinputbuffer.c b/src/openrct2/core/textinputbuffer.c
index 0a73b78487..4463f58f6c 100644
--- a/src/openrct2/core/textinputbuffer.c
+++ b/src/openrct2/core/textinputbuffer.c
@@ -74,7 +74,7 @@ void textinputbuffer_insert_codepoint(textinputbuffer * tib, uint32 codepoint)
     }
 }
 
-void textinputbuffer_insert(textinputbuffer * tib, utf8 * source)
+void textinputbuffer_insert(textinputbuffer * tib, const utf8 * source)
 {
     const utf8 *ch = source;
     uint32 codepoint;
diff --git a/src/openrct2/core/textinputbuffer.h b/src/openrct2/core/textinputbuffer.h
index cbf9dcdd1e..12f4807528 100644
--- a/src/openrct2/core/textinputbuffer.h
+++ b/src/openrct2/core/textinputbuffer.h
@@ -34,7 +34,7 @@ void textinputbuffer_init(textinputbuffer * tib, utf8 * buffer, size_t size);
 void textinputbuffer_clear(textinputbuffer * tib);
 void textinputbuffer_remove_selected(textinputbuffer * tib);
 void textinputbuffer_insert_codepoint(textinputbuffer * tib, uint32 codepoint);
-void textinputbuffer_insert(textinputbuffer * tib, utf8 * source);
+void textinputbuffer_insert(textinputbuffer * tib, const utf8 * source);
 void textinputbuffer_cursor_left(textinputbuffer * tib);
 void textinputbuffer_cursor_right(textinputbuffer * tib);
 void textinputbuffer_cursor_home(textinputbuffer * tib);
diff --git a/src/openrct2/drawing/Drawing.h b/src/openrct2/drawing/Drawing.h
index 134cbb6f89..7614da6fde 100644
--- a/src/openrct2/drawing/Drawing.h
+++ b/src/openrct2/drawing/Drawing.h
@@ -308,7 +308,7 @@ bool is_csg_loaded();
 uint32 gfx_object_allocate_images(const rct_g1_element * images, uint32 count);
 void gfx_object_free_images(uint32 baseImageId, uint32 count);
 void gfx_object_check_all_images_freed();
-void FASTCALL gfx_bmp_sprite_to_buffer(uint8* palette_pointer, uint8* unknown_pointer, uint8* source_pointer, uint8* dest_pointer, const rct_g1_element* source_image, rct_drawpixelinfo *dest_dpi, sint32 height, sint32 width, sint32 image_type);
+void FASTCALL gfx_bmp_sprite_to_buffer(const uint8* palette_pointer, uint8* unknown_pointer, uint8* source_pointer, uint8* dest_pointer, const rct_g1_element* source_image, rct_drawpixelinfo *dest_dpi, sint32 height, sint32 width, sint32 image_type);
 void FASTCALL gfx_rle_sprite_to_buffer(const uint8* RESTRICT source_bits_pointer, uint8* RESTRICT dest_bits_pointer, const uint8* RESTRICT palette_pointer, const rct_drawpixelinfo * RESTRICT dpi, sint32 image_type, sint32 source_y_start, sint32 height, sint32 source_x_start, sint32 width);
 void FASTCALL gfx_draw_sprite(rct_drawpixelinfo *dpi, sint32 image_id, sint32 x, sint32 y, uint32 tertiary_colour);
 void FASTCALL gfx_draw_glpyh(rct_drawpixelinfo *dpi, sint32 image_id, sint32 x, sint32 y, uint8 * palette);
diff --git a/src/openrct2/drawing/LightFX.cpp b/src/openrct2/drawing/LightFX.cpp
index 6fa2ac6631..92610e2b01 100644
--- a/src/openrct2/drawing/LightFX.cpp
+++ b/src/openrct2/drawing/LightFX.cpp
@@ -981,8 +981,8 @@ void lightfx_render_to_texture(
     uint8 * bits,
     uint32 width,
     uint32 height,
-    uint32 * palette,
-    uint32 * lightPalette)
+    const uint32 * palette,
+    const uint32 * lightPalette)
 {
     lightfx_update_viewport_settings();
     lightfx_swap_buffers();
diff --git a/src/openrct2/drawing/LightFX.h b/src/openrct2/drawing/LightFX.h
index 91e8bf8406..d854bbe340 100644
--- a/src/openrct2/drawing/LightFX.h
+++ b/src/openrct2/drawing/LightFX.h
@@ -79,8 +79,8 @@ void lightfx_render_to_texture(
     uint8 * bits,
     uint32 width,
     uint32 height,
-    uint32 * palette,
-    uint32 * lightPalette);
+    const uint32 * palette,
+    const uint32 * lightPalette);
 
 #ifdef __cplusplus
 }
diff --git a/src/openrct2/drawing/Sprite.cpp b/src/openrct2/drawing/Sprite.cpp
index fb822773c6..99e686202f 100644
--- a/src/openrct2/drawing/Sprite.cpp
+++ b/src/openrct2/drawing/Sprite.cpp
@@ -390,7 +390,7 @@ extern "C"
      * image.
      *  rct2: 0x0067A690
      */
-    void FASTCALL gfx_bmp_sprite_to_buffer(uint8* palette_pointer, uint8* unknown_pointer, uint8* source_pointer, uint8* dest_pointer, const rct_g1_element* source_image, rct_drawpixelinfo *dest_dpi, sint32 height, sint32 width, sint32 image_type)
+    void FASTCALL gfx_bmp_sprite_to_buffer(const uint8* palette_pointer, uint8* unknown_pointer, uint8* source_pointer, uint8* dest_pointer, const rct_g1_element* source_image, rct_drawpixelinfo *dest_dpi, sint32 height, sint32 width, sint32 image_type)
     {
         uint16 zoom_level = dest_dpi->zoom_level;
         uint8 zoom_amount = 1 << zoom_level;
diff --git a/src/openrct2/drawing/String.cpp b/src/openrct2/drawing/String.cpp
index 7fbb986e37..c596f01274 100644
--- a/src/openrct2/drawing/String.cpp
+++ b/src/openrct2/drawing/String.cpp
@@ -230,7 +230,7 @@ void gfx_draw_string_left_centred(rct_drawpixelinfo *dpi, rct_string_id format,
 /**
  * Changes the palette so that the next character changes colour
  */
-static void colour_char(uint8 colour, uint16* current_font_flags, uint8* palette_pointer) {
+static void colour_char(uint8 colour, const uint16* current_font_flags, uint8* palette_pointer) {
 
     sint32 colour32 = 0;
     const rct_g1_element * g1 = gfx_get_g1_element(SPR_TEXT_PALETTE);
@@ -254,7 +254,7 @@ static void colour_char(uint8 colour, uint16* current_font_flags, uint8* palette
  * Changes the palette so that the next character changes colour
  * This is specific to changing to a predefined window related colour
  */
-static void colour_char_window(uint8 colour, uint16* current_font_flags,uint8* palette_pointer) {
+static void colour_char_window(uint8 colour, const uint16* current_font_flags,uint8* palette_pointer) {
 
     sint32 eax;
 
diff --git a/src/openrct2/interface/Viewport.cpp b/src/openrct2/interface/Viewport.cpp
index b3624e4f24..6297394f37 100644
--- a/src/openrct2/interface/Viewport.cpp
+++ b/src/openrct2/interface/Viewport.cpp
@@ -1203,7 +1203,7 @@ static bool pixel_is_present_bmp(uint32 imageType, const rct_g1_element * g1, co
 /**
  * rct2: 0x0067933B, 0x00679788, 0x00679C4A, 0x0067A117
  */
-static bool is_pixel_present_rle(uint8 *esi, sint16 x_start_point, sint16 y_start_point, sint32 round) {
+static bool is_pixel_present_rle(const uint8 *esi, sint16 x_start_point, sint16 y_start_point, sint32 round) {
     const uint8 *ebx = esi + ((uint16 *) esi)[y_start_point];
 
     uint8 last_data_line = 0;
diff --git a/src/openrct2/peep/Peep.cpp b/src/openrct2/peep/Peep.cpp
index 567a29f3c6..600aa50feb 100644
--- a/src/openrct2/peep/Peep.cpp
+++ b/src/openrct2/peep/Peep.cpp
@@ -2561,7 +2561,7 @@ void remove_peep_from_queue(rct_peep * peep)
  *
  *  rct2: 0x00691C6E
  */
-static rct_vehicle * peep_choose_car_from_ride(rct_peep * peep, Ride * ride, uint8 * car_array, uint8 car_array_size)
+static rct_vehicle * peep_choose_car_from_ride(rct_peep * peep, Ride * ride, const uint8 * car_array, uint8 car_array_size)
 {
     uint8 chosen_car = peep_rand();
     if (ride_type_has_flag(ride->type, RIDE_TYPE_FLAG_HAS_G_FORCES) && ((chosen_car & 0xC) != 0xC))