diff --git a/src/dehacked.c b/src/dehacked.c
index 0e7ddb7e5..829f03343 100644
--- a/src/dehacked.c
+++ b/src/dehacked.c
@@ -1230,8 +1230,9 @@ static void readlevelheader(MYFILE *f, INT32 num)
 			}
 			else if (fastcmp(word, "WEATHER"))
 				mapheaderinfo[num-1]->weather = (UINT8)get_number(word2);
-			else if (fastcmp(word, "SKYNUM"))
-				mapheaderinfo[num-1]->skynum = (INT16)i;
+			else if (fastcmp(word, "SKYTEXTURE"))
+				deh_strlcpy(mapheaderinfo[num-1]->skytexture, word2,
+					sizeof(mapheaderinfo[num-1]->skytexture), va("Level header %d: sky texture", num));
 			else if (fastcmp(word, "INTERSCREEN"))
 				strncpy(mapheaderinfo[num-1]->interscreen, word2, 8);
 			else if (fastcmp(word, "PRECUTSCENENUM"))
@@ -9926,11 +9927,11 @@ static inline int lib_getenum(lua_State *L)
 	} else if (fastcmp(word,"globalweather")) {
 		lua_pushinteger(L, globalweather);
 		return 1;
-	} else if (fastcmp(word,"levelskynum")) {
-		lua_pushinteger(L, levelskynum);
+	} else if (fastcmp(word,"levelskytexture")) {
+		lua_pushstring(L, levelskytexture);
 		return 1;
-	} else if (fastcmp(word,"globallevelskynum")) {
-		lua_pushinteger(L, globallevelskynum);
+	} else if (fastcmp(word,"globallevelskytexture")) {
+		lua_pushstring(L, globallevelskytexture);
 		return 1;
 	} else if (fastcmp(word,"mapmusname")) {
 		lua_pushstring(L, mapmusname);
diff --git a/src/doomstat.h b/src/doomstat.h
index 2299e8e87..1f0182c7d 100644
--- a/src/doomstat.h
+++ b/src/doomstat.h
@@ -227,7 +227,7 @@ typedef struct
 	UINT32 muspos;    ///< Music position to jump to.
 	char forcecharacter[17];  ///< (SKINNAMESIZE+1) Skin to switch to or "" to disable.
 	UINT8 weather;         ///< 0 = sunny day, 1 = storm, 2 = snow, 3 = rain, 4 = blank, 5 = thunder w/o rain, 6 = rain w/o lightning, 7 = heat wave.
-	INT16 skynum;          ///< Sky number to use.
+	char skytexture[9];    ///< Sky texture to use.
 	INT16 skybox_scalex;   ///< Skybox X axis scale. (0 = no movement, 1 = 1:1 movement, 16 = 16:1 slow movement, -4 = 1:4 fast movement, etc.)
 	INT16 skybox_scaley;   ///< Skybox Y axis scale.
 	INT16 skybox_scalez;   ///< Skybox Z axis scale.
diff --git a/src/hardware/hw_main.c b/src/hardware/hw_main.c
index 0d024dc65..659af386d 100644
--- a/src/hardware/hw_main.c
+++ b/src/hardware/hw_main.c
@@ -5922,13 +5922,15 @@ static void HWR_ProjectPrecipitationSprite(precipmobj_t *thing)
 static void HWR_DrawSkyBackground(void)
 {
 	FOutVector v[4];
+	texture_t *tex;
 	angle_t angle;
 	float dimensionmultiply;
 	float aspectratio;
 	float angleturn;
 
+	tex = textures[texturetranslation[skytexture]];
 	HWR_GetTexture(texturetranslation[skytexture]);
-	aspectratio = (float)vid.width/(float)vid.height;
+	aspectratio = (float)vid.width / (float)vid.height;
 
 	//Hurdler: the sky is the only texture who need 4.0f instead of 1.0
 	//         because it's called just after clearing the screen
@@ -5952,22 +5954,22 @@ static void HWR_DrawSkyBackground(void)
 	// software doesn't draw any further than 1024 for skies anyway, but this doesn't overlap properly
 	// The only time this will probably be an issue is when a sky wider than 1024 is used as a sky AND a regular wall texture
 
-	angle = (dup_viewangle + gr_xtoviewangle[0]);
-	dimensionmultiply = ((float)textures[texturetranslation[skytexture]]->width/256.0f);
+	angle = -(dup_viewangle + gr_xtoviewangle[0]);
+	dimensionmultiply = ((float)tex->width/256.0f);
 
 	if (atransform.mirror)
 	{
 		angle = InvAngle(angle);
-		dimensionmultiply *= -1;
+		dimensionmultiply = -dimensionmultiply;
 	}
 
 	v[0].sow = v[3].sow = ((float) angle / ((ANGLE_90-1)*dimensionmultiply));
-	v[2].sow = v[1].sow = (-1.0f/dimensionmultiply)+((float) angle / ((ANGLE_90-1)*dimensionmultiply));
+	v[2].sow = v[1].sow = (1.0f/dimensionmultiply)+((float) angle / ((ANGLE_90-1)*dimensionmultiply));
 
 	// Y
 	angle = aimingangle;
 
-	dimensionmultiply = ((float)textures[texturetranslation[skytexture]]->height/(128.0f*aspectratio));
+	dimensionmultiply = ((float)tex->height/(128.0f*aspectratio));
 
 	if (splitscreen == 1)
 	{
diff --git a/src/lua_baselib.c b/src/lua_baselib.c
index 38af4d2e9..7464743c3 100644
--- a/src/lua_baselib.c
+++ b/src/lua_baselib.c
@@ -1405,15 +1405,15 @@ static int lib_pIsFlagAtBase(lua_State *L)
 
 static int lib_pSetupLevelSky(lua_State *L)
 {
-	INT32 skynum = (INT32)luaL_checkinteger(L, 1);
+	const char *skytexname = luaL_checkstring(L, 1);
 	player_t *user = NULL;
 	NOHUD
 	if (!lua_isnone(L, 2) && lua_isuserdata(L, 2)) // if a player, setup sky for only the player, otherwise setup sky for all players
 		user = *((player_t **)luaL_checkudata(L, 2, META_PLAYER));
 	if (!user) // global
-		P_SetupLevelSky(skynum, true);
+		P_SetupLevelSky(skytexname, true);
 	else if (P_IsLocalPlayer(user))
-		P_SetupLevelSky(skynum, false);
+		P_SetupLevelSky(skytexname, false);
 	return 0;
 }
 
diff --git a/src/lua_maplib.c b/src/lua_maplib.c
index 19292b3d6..0522cb737 100644
--- a/src/lua_maplib.c
+++ b/src/lua_maplib.c
@@ -1487,8 +1487,8 @@ static int mapheaderinfo_get(lua_State *L)
 		lua_pushstring(L, header->forcecharacter);
 	else if (fastcmp(field,"weather"))
 		lua_pushinteger(L, header->weather);
-	else if (fastcmp(field,"skynum"))
-		lua_pushinteger(L, header->skynum);
+	else if (fastcmp(field,"skytexture"))
+		lua_pushstring(L, header->skytexture);
 	else if (fastcmp(field,"skybox_scalex"))
 		lua_pushinteger(L, header->skybox_scalex);
 	else if (fastcmp(field,"skybox_scaley"))
diff --git a/src/m_cheat.c b/src/m_cheat.c
index e7e877ada..c24a8014b 100644
--- a/src/m_cheat.c
+++ b/src/m_cheat.c
@@ -577,14 +577,14 @@ void Command_Skynum_f(void)
 
 	if (COM_Argc() != 2)
 	{
-		CONS_Printf(M_GetText("skynum <sky#>: change the sky\n"));
-		CONS_Printf(M_GetText("Current sky is %d\n"), levelskynum);
+		CONS_Printf(M_GetText("skynum <texture name>: change the sky\n"));
+		CONS_Printf(M_GetText("Current sky is %s\n"), levelskytexture);
 		return;
 	}
 
 	CONS_Printf(M_GetText("Previewing sky %s...\n"), COM_Argv(1));
 
-	P_SetupLevelSky(atoi(COM_Argv(1)), false);
+	P_SetupLevelSky(COM_Argv(1), false);
 }
 
 void Command_Weather_f(void)
diff --git a/src/p_saveg.c b/src/p_saveg.c
index a3b80633a..e083c2c5b 100644
--- a/src/p_saveg.c
+++ b/src/p_saveg.c
@@ -3096,7 +3096,7 @@ static inline void P_NetArchiveSpecials(void)
 	WRITEUINT32(save_p, 0xffffffff);
 
 	// Sky number
-	WRITEINT32(save_p, globallevelskynum);
+	WRITESTRINGN(save_p, globallevelskytexture, 9);
 
 	// Current global weather type
 	WRITEUINT8(save_p, globalweather);
@@ -3115,8 +3115,8 @@ static inline void P_NetArchiveSpecials(void)
 //
 static void P_NetUnArchiveSpecials(void)
 {
+	char skytex[9];
 	size_t i;
-	INT32 j;
 
 	if (READUINT32(save_p) != ARCHIVEBLOCK_SPECIALS)
 		I_Error("Bad $$$.sav at archive block Specials");
@@ -3129,9 +3129,9 @@ static void P_NetUnArchiveSpecials(void)
 		itemrespawntime[iquehead++] = READINT32(save_p);
 	}
 
-	j = READINT32(save_p);
-	if (j != globallevelskynum)
-		P_SetupLevelSky(j, true);
+	READSTRINGN(save_p, skytex, sizeof(skytex));
+	if (strcmp(skytex, globallevelskytexture))
+		P_SetupLevelSky(skytex, true);
 
 	globalweather = READUINT8(save_p);
 
diff --git a/src/p_setup.c b/src/p_setup.c
index d1ef91705..b7a482ce9 100644
--- a/src/p_setup.c
+++ b/src/p_setup.c
@@ -207,8 +207,9 @@ static void P_ClearSingleMapHeaderInfo(INT16 i)
 	mapheaderinfo[num]->forcecharacter[0] = '\0';
 	DEH_WriteUndoline("WEATHER", va("%d", mapheaderinfo[num]->weather), UNDO_NONE);
 	mapheaderinfo[num]->weather = 0;
-	DEH_WriteUndoline("SKYNUM", va("%d", mapheaderinfo[num]->skynum), UNDO_NONE);
-	mapheaderinfo[num]->skynum = 1;
+	DEH_WriteUndoline("SKYTEXTURE", va("%d", mapheaderinfo[num]->skytexture), UNDO_NONE);
+	snprintf(mapheaderinfo[num]->skytexture, 9, "SKY1");
+	mapheaderinfo[num]->skytexture[8] = 0;
 	DEH_WriteUndoline("SKYBOXSCALEX", va("%d", mapheaderinfo[num]->skybox_scalex), UNDO_NONE);
 	mapheaderinfo[num]->skybox_scalex = 16;
 	DEH_WriteUndoline("SKYBOXSCALEY", va("%d", mapheaderinfo[num]->skybox_scaley), UNDO_NONE);
@@ -2255,17 +2256,18 @@ static inline boolean P_CheckLevel(lumpnum_t lumpnum)
 /** Sets up a sky texture to use for the level.
   * The sky texture is used instead of F_SKY1.
   */
-void P_SetupLevelSky(INT32 skynum, boolean global)
+void P_SetupLevelSky(const char *skytexname, boolean global)
 {
-	char skytexname[12];
+	char tex[9];
+	strncpy(tex, skytexname, 9);
+	tex[8] = 0;
 
-	sprintf(skytexname, "SKY%d", skynum);
-	skytexture = R_TextureNumForName(skytexname);
-	levelskynum = skynum;
+	skytexture = R_TextureNumForName(tex);
+	strncpy(levelskytexture, tex, 9);
 
 	// Global change
 	if (global)
-		globallevelskynum = levelskynum;
+		strncpy(globallevelskytexture, tex, 9);
 
 	// Don't go beyond for dedicated servers
 	if (dedicated)
@@ -2973,7 +2975,7 @@ boolean P_SetupLevel(boolean skipprecip)
 	CON_SetupBackColormap();
 
 	// SRB2 determines the sky texture to be used depending on the map header.
-	P_SetupLevelSky(mapheaderinfo[gamemap-1]->skynum, true);
+	P_SetupLevelSky(mapheaderinfo[gamemap-1]->skytexture, true);
 
 	P_MakeMapMD5(lastloadedmaplumpnum, &mapmd5);
 
diff --git a/src/p_setup.h b/src/p_setup.h
index c4a3aab9a..9abcfe5f6 100644
--- a/src/p_setup.h
+++ b/src/p_setup.h
@@ -54,7 +54,7 @@ INT32 P_CheckLevelFlat(const char *flatname);
 extern size_t nummapthings;
 extern mapthing_t *mapthings;
 
-void P_SetupLevelSky(INT32 skynum, boolean global);
+void P_SetupLevelSky(const char *skytexname, boolean global);
 #ifdef SCANTHINGS
 void P_ScanThings(INT16 mapnum, INT16 wadnum, INT16 lumpnum);
 #endif
diff --git a/src/p_spec.c b/src/p_spec.c
index ec5de3224..daef60a09 100644
--- a/src/p_spec.c
+++ b/src/p_spec.c
@@ -2802,7 +2802,7 @@ static void P_ProcessLineSpecial(line_t *line, mobj_t *mo, sector_t *callsec)
 
 		case 423: // Change Sky
 			if ((mo && mo->player && P_IsLocalPlayer(mo->player)) || (line->flags & ML_NOCLIMB))
-				P_SetupLevelSky(sides[line->sidenum[0]].textureoffset>>FRACBITS, (line->flags & ML_NOCLIMB));
+				P_SetupLevelSky(sides[line->sidenum[0]].text, (line->flags & ML_NOCLIMB));
 			break;
 
 		case 424: // Change Weather
diff --git a/src/r_data.c b/src/r_data.c
index 7fb11855f..d710359d1 100644
--- a/src/r_data.c
+++ b/src/r_data.c
@@ -1631,7 +1631,7 @@ void R_PrecacheLevel(void)
 
 	// Sky texture is always present.
 	// Note that F_SKY1 is the name used to indicate a sky floor/ceiling as a flat,
-	// while the sky texture is stored like a wall texture, with a skynum dependent name.
+	// while the sky texture is stored like a wall texture, with a texture name set by the map.
 	texturepresent[skytexture] = 1;
 
 	texturememory = 0;
diff --git a/src/r_plane.c b/src/r_plane.c
index db5bfbda2..ec105bf75 100644
--- a/src/r_plane.c
+++ b/src/r_plane.c
@@ -734,7 +734,7 @@ void R_DrawPlanes(void)
 						dc_x = x;
 						dc_source =
 							R_GetColumn(texturetranslation[skytexture],
-								angle);
+								-angle); // Negative because skies were being drawn horizontally flipped
 						wallcolfunc();
 					}
 				}
diff --git a/src/r_sky.c b/src/r_sky.c
index fe1630e90..1fe0fe0e6 100644
--- a/src/r_sky.c
+++ b/src/r_sky.c
@@ -47,8 +47,8 @@ fixed_t skyscale;
 
 /** \brief used for keeping track of the current sky
 */
-INT32 levelskynum;
-INT32 globallevelskynum;
+char levelskytexture[9];
+char globallevelskytexture[9];
 
 /**	\brief	The R_SetupSkyDraw function
 
diff --git a/src/r_sky.h b/src/r_sky.h
index 86b615595..a41b24463 100644
--- a/src/r_sky.h
+++ b/src/r_sky.h
@@ -30,8 +30,8 @@ extern INT32 skytexture, skytexturemid;
 extern fixed_t skyscale;
 
 extern INT32 skyflatnum;
-extern INT32 levelskynum;
-extern INT32 globallevelskynum;
+extern char levelskytexture[9];
+extern char globallevelskytexture[9];
 
 // call after skytexture is set to adapt for old/new skies
 void R_SetupSkyDraw(void);