diff --git a/src/gfx.cpp b/src/gfx.cpp
index 97ae0f510e..5165fe01c4 100644
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -58,8 +58,8 @@ static void GfxMainBlitter(const Sprite *sprite, int x, int y, BlitterMode mode,
 
 static ReusableBuffer<uint8> _cursor_backup;
 
-ZoomLevelByte _gui_zoom; ///< GUI Zoom level
-ZoomLevelByte _font_zoom; ///< Font Zoom level
+ZoomLevel _gui_zoom; ///< GUI Zoom level
+ZoomLevel _font_zoom; ///< Font Zoom level
 
 /**
  * The rect for repaint.
diff --git a/src/saveload/afterload.cpp b/src/saveload/afterload.cpp
index 8d9b0ffa6c..b5095c521f 100644
--- a/src/saveload/afterload.cpp
+++ b/src/saveload/afterload.cpp
@@ -2834,7 +2834,7 @@ bool AfterLoadGame()
 
 	if (IsSavegameVersionBefore(SLV_165)) {
 		/* Adjust zoom level to account for new levels */
-		_saved_scrollpos_zoom = _saved_scrollpos_zoom + ZOOM_LVL_SHIFT;
+		_saved_scrollpos_zoom = static_cast<ZoomLevel>(_saved_scrollpos_zoom + ZOOM_LVL_SHIFT);
 		_saved_scrollpos_x *= ZOOM_LVL_BASE;
 		_saved_scrollpos_y *= ZOOM_LVL_BASE;
 	}
diff --git a/src/saveload/misc_sl.cpp b/src/saveload/misc_sl.cpp
index f0b1309527..4a9b05a461 100644
--- a/src/saveload/misc_sl.cpp
+++ b/src/saveload/misc_sl.cpp
@@ -30,7 +30,7 @@ extern byte _trees_tick_ctr;
 /* Keep track of current game position */
 int _saved_scrollpos_x;
 int _saved_scrollpos_y;
-ZoomLevelByte _saved_scrollpos_zoom;
+ZoomLevel _saved_scrollpos_zoom;
 
 void SaveViewportBeforeSaveGame()
 {
diff --git a/src/saveload/saveload_internal.h b/src/saveload/saveload_internal.h
index 74e5b9936d..e7a9e7bf5e 100644
--- a/src/saveload/saveload_internal.h
+++ b/src/saveload/saveload_internal.h
@@ -49,7 +49,7 @@ void CopyTempEngineData();
 
 extern int32 _saved_scrollpos_x;
 extern int32 _saved_scrollpos_y;
-extern ZoomLevelByte _saved_scrollpos_zoom;
+extern ZoomLevel _saved_scrollpos_zoom;
 
 extern SavegameType _savegame_type;
 extern uint32 _ttdp_version;
diff --git a/src/settings_type.h b/src/settings_type.h
index 2459058979..d164be431d 100644
--- a/src/settings_type.h
+++ b/src/settings_type.h
@@ -107,8 +107,8 @@ struct GUISettings {
 	uint8  statusbar_pos;                    ///< position of statusbar, 0=left, 1=center, 2=right
 	uint8  window_snap_radius;               ///< windows snap at each other if closer than this
 	uint8  window_soft_limit;                ///< soft limit of maximum number of non-stickied non-vital windows (0 = no limit)
-	ZoomLevelByte zoom_min;                  ///< minimum zoom out level
-	ZoomLevelByte zoom_max;                  ///< maximum zoom out level
+	ZoomLevel zoom_min;                      ///< minimum zoom out level
+	ZoomLevel zoom_max;                      ///< maximum zoom out level
 	bool   disable_unsuitable_building;      ///< disable infrastructure building when no suitable vehicles are available
 	byte   autosave;                         ///< how often should we do autosaves?
 	bool   threaded_saves;                   ///< should we do threaded saves?
diff --git a/src/viewport.cpp b/src/viewport.cpp
index 8ec315b16d..8a1319072c 100644
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -1692,7 +1692,7 @@ void ViewportDoDraw(const ViewPort *vp, int left, int top, int right, int bottom
  */
 static void ViewportDrawChk(const ViewPort *vp, int left, int top, int right, int bottom)
 {
-	if (ScaleByZoom(bottom - top, vp->zoom) * ScaleByZoom(right - left, vp->zoom) > 180000 * ZOOM_LVL_BASE * ZOOM_LVL_BASE) {
+	if (ScaleByZoom(bottom - top, vp->zoom) * ScaleByZoom(right - left, vp->zoom) > (int)(180000 * ZOOM_LVL_BASE * ZOOM_LVL_BASE)) {
 		if ((bottom - top) > (right - left)) {
 			int t = (top + bottom) >> 1;
 			ViewportDrawChk(vp, left, top, right, t);
diff --git a/src/zoom_func.h b/src/zoom_func.h
index 0e8fa8c9ef..dff7322a03 100644
--- a/src/zoom_func.h
+++ b/src/zoom_func.h
@@ -23,7 +23,6 @@
  */
 static inline int ScaleByZoom(int value, ZoomLevel zoom)
 {
-	assert(zoom >= 0);
 	return value << zoom;
 }
 
@@ -36,7 +35,6 @@ static inline int ScaleByZoom(int value, ZoomLevel zoom)
  */
 static inline int UnScaleByZoom(int value, ZoomLevel zoom)
 {
-	assert(zoom >= 0);
 	return (value + (1 << zoom) - 1) >> zoom;
 }
 
@@ -48,7 +46,6 @@ static inline int UnScaleByZoom(int value, ZoomLevel zoom)
  */
 static inline int ScaleByZoomLower(int value, ZoomLevel zoom)
 {
-	assert(zoom >= 0);
 	return value << zoom;
 }
 
@@ -60,7 +57,6 @@ static inline int ScaleByZoomLower(int value, ZoomLevel zoom)
  */
 static inline int UnScaleByZoomLower(int value, ZoomLevel zoom)
 {
-	assert(zoom >= 0);
 	return value >> zoom;
 }
 
diff --git a/src/zoom_type.h b/src/zoom_type.h
index ea8302761f..47a725df2b 100644
--- a/src/zoom_type.h
+++ b/src/zoom_type.h
@@ -14,11 +14,11 @@
 
 #include "core/enum_type.hpp"
 
-static int const ZOOM_LVL_SHIFT = 2;
-static int const ZOOM_LVL_BASE  = 1 << ZOOM_LVL_SHIFT;
+static uint const ZOOM_LVL_SHIFT = 2;
+static uint const ZOOM_LVL_BASE  = 1 << ZOOM_LVL_SHIFT;
 
 /** All zoom levels we know. */
-enum ZoomLevel {
+enum ZoomLevel : byte {
 	/* Our possible zoom-levels */
 	ZOOM_LVL_BEGIN  = 0, ///< Begin for iteration.
 	ZOOM_LVL_NORMAL = 0, ///< The normal zoom level.
@@ -46,14 +46,12 @@ enum ZoomLevel {
 
 	ZOOM_LVL_MIN      = ZOOM_LVL_NORMAL, ///< Minimum zoom level.
 	ZOOM_LVL_MAX      = ZOOM_LVL_OUT_32X, ///< Maximum zoom level.
+
 };
 DECLARE_POSTFIX_INCREMENT(ZoomLevel)
 
-/** Type for storing the zoom level in a byte. */
-typedef SimpleTinyEnumT<ZoomLevel, byte> ZoomLevelByte;
-
-extern ZoomLevelByte _gui_zoom;
-extern ZoomLevelByte _font_zoom;
+extern ZoomLevel _gui_zoom;
+extern ZoomLevel _font_zoom;
 #define ZOOM_LVL_GUI (_gui_zoom)
 #define ZOOM_LVL_FONT (_font_zoom)