diff --git a/src/common/rendering/gl/gl_renderstate.cpp b/src/common/rendering/gl/gl_renderstate.cpp
index 9eee22c66..5628ca0a5 100644
--- a/src/common/rendering/gl/gl_renderstate.cpp
+++ b/src/common/rendering/gl/gl_renderstate.cpp
@@ -142,6 +142,9 @@ bool FGLRenderState::ApplyShader()
 	activeShader->muTextureModulateColor.Set(mStreamData.uTextureModulateColor);
 	activeShader->muTextureBlendColor.Set(mStreamData.uTextureBlendColor);
 	activeShader->muDetailParms.Set(&mStreamData.uDetailParms.X);
+#ifdef NPOT_EMULATION
+	activeShader->muNpotEmulation.Set(&mStreamData.uNpotEmulation.X);
+#endif
 
 	if (mGlowEnabled || activeShader->currentglowstate)
 	{
diff --git a/src/common/rendering/gl/gl_shader.cpp b/src/common/rendering/gl/gl_shader.cpp
index 51f3fb3eb..0505a1d2e 100644
--- a/src/common/rendering/gl/gl_shader.cpp
+++ b/src/common/rendering/gl/gl_shader.cpp
@@ -40,6 +40,7 @@
 #include "hw_lightbuffer.h"
 #include "i_specialpaths.h"
 #include "printf.h"
+#include "version.h"
 
 #include "gl_interface.h"
 #include "gl_debug.h"
@@ -232,105 +233,106 @@ bool FShader::Load(const char * name, const char * vert_prog_lump, const char *
 			float uClipHeightDirection;
 			int uShadowmapFilter;
 		};
+
+		uniform int uTextureMode;
+		uniform vec2 uClipSplit;
+		uniform float uAlphaThreshold;
+
+		// colors
+		uniform vec4 uObjectColor;
+		uniform vec4 uObjectColor2;
+		uniform vec4 uDynLightColor;
+		uniform vec4 uAddColor;
+		uniform vec4 uTextureBlendColor;
+		uniform vec4 uTextureModulateColor;
+		uniform vec4 uTextureAddColor;
+		uniform vec4 uBlendColor;
+		uniform vec4 uFogColor;
+		uniform float uDesaturationFactor;
+		uniform float uInterpolationFactor;
+
+		// Glowing walls stuff
+		uniform vec4 uGlowTopPlane;
+		uniform vec4 uGlowTopColor;
+		uniform vec4 uGlowBottomPlane;
+		uniform vec4 uGlowBottomColor;
+
+		uniform vec4 uGradientTopPlane;
+		uniform vec4 uGradientBottomPlane;
+
+		uniform vec4 uSplitTopPlane;
+		uniform vec4 uSplitBottomPlane;
+
+		uniform vec4 uDetailParms;
+		// Lighting + Fog
+		uniform vec4 uLightAttr;
+		#define uLightLevel uLightAttr.a
+		#define uFogDensity uLightAttr.b
+		#define uLightFactor uLightAttr.g
+		#define uLightDist uLightAttr.r
+		uniform int uFogEnabled;
+
+		// dynamic lights
+		uniform int uLightIndex;
+
+		// Blinn glossiness and specular level
+		uniform vec2 uSpecularMaterial;
+
+		// matrices
+		uniform mat4 ModelMatrix;
+		uniform mat4 NormalModelMatrix;
+		uniform mat4 TextureMatrix;
+
+		// light buffers
+		#ifdef SHADER_STORAGE_LIGHTS
+		layout(std430, binding = 1) buffer LightBufferSSO
+		{
+			vec4 lights[];
+		};
+		#elif defined NUM_UBO_LIGHTS
+		uniform LightBufferUBO
+		{
+			vec4 lights[NUM_UBO_LIGHTS];
+		};
+		#endif
+
+		// textures
+		uniform sampler2D tex;
+		uniform sampler2D ShadowMap;
+		uniform sampler2D texture2;
+		uniform sampler2D texture3;
+		uniform sampler2D texture4;
+		uniform sampler2D texture5;
+		uniform sampler2D texture6;
+		uniform sampler2D texture7;
+		uniform sampler2D texture8;
+
+		// timer data
+		uniform float timer;
+
+		// material types
+		#if defined(SPECULAR)
+		#define normaltexture texture2
+		#define speculartexture texture3
+		#define brighttexture texture4
+		#define detailtexture texture5
+		#define glowtexture texture6
+		#elif defined(PBR)
+		#define normaltexture texture2
+		#define metallictexture texture3
+		#define roughnesstexture texture4
+		#define aotexture texture5
+		#define brighttexture texture6
+		#define detailtexture texture7
+		#define glowtexture texture8
+		#else
+		#define brighttexture texture2
+		#define detailtexture texture3
+		#define glowtexture texture4
+		#endif
+
 	)";
 	
-	i_data += "uniform int uTextureMode;\n";
-	i_data += "uniform vec2 uClipSplit;\n";
-	i_data += "uniform float uAlphaThreshold;\n";
-
-	// colors
-	i_data += "uniform vec4 uObjectColor;\n";
-	i_data += "uniform vec4 uObjectColor2;\n";
-	i_data += "uniform vec4 uDynLightColor;\n";
-	i_data += "uniform vec4 uAddColor;\n";
-	i_data += "uniform vec4 uTextureBlendColor;\n";
-	i_data += "uniform vec4 uTextureModulateColor;\n";
-	i_data += "uniform vec4 uTextureAddColor;\n";
-	i_data += "uniform vec4 uBlendColor;\n";
-	i_data += "uniform vec4 uFogColor;\n";
-	i_data += "uniform float uDesaturationFactor;\n";
-	i_data += "uniform float uInterpolationFactor;\n";
-
-	// Glowing walls stuff
-	i_data += "uniform vec4 uGlowTopPlane;\n";
-	i_data += "uniform vec4 uGlowTopColor;\n";
-	i_data += "uniform vec4 uGlowBottomPlane;\n";
-	i_data += "uniform vec4 uGlowBottomColor;\n";
-
-	i_data += "uniform vec4 uGradientTopPlane;\n";
-	i_data += "uniform vec4 uGradientBottomPlane;\n";
-
-	i_data += "uniform vec4 uSplitTopPlane;\n";
-	i_data += "uniform vec4 uSplitBottomPlane;\n";
-
-	i_data += "uniform vec4 uDetailParms;\n";
-
-	// Lighting + Fog
-	i_data += "uniform vec4 uLightAttr;\n";
-	i_data += "#define uLightLevel uLightAttr.a\n";
-	i_data += "#define uFogDensity uLightAttr.b\n";
-	i_data += "#define uLightFactor uLightAttr.g\n";
-	i_data += "#define uLightDist uLightAttr.r\n";
-	i_data += "uniform int uFogEnabled;\n";
-
-	// dynamic lights
-	i_data += "uniform int uLightIndex;\n";
-
-	// Blinn glossiness and specular level
-	i_data += "uniform vec2 uSpecularMaterial;\n";
-
-	// matrices
-	i_data += "uniform mat4 ModelMatrix;\n";
-	i_data += "uniform mat4 NormalModelMatrix;\n";
-	i_data += "uniform mat4 TextureMatrix;\n";
-
-	// light buffers
-	i_data += "#ifdef SHADER_STORAGE_LIGHTS\n";
-	i_data += "layout(std430, binding = 1) buffer LightBufferSSO\n";
-	i_data += "{\n";
-	i_data += "    vec4 lights[];\n";
-	i_data += "};\n";
-	i_data += "#elif defined NUM_UBO_LIGHTS\n";
-	i_data += "uniform LightBufferUBO\n";
-	i_data += "{\n";
-	i_data += "    vec4 lights[NUM_UBO_LIGHTS];\n";
-	i_data += "};\n";
-	i_data += "#endif\n";
-
-	// textures
-	i_data += "uniform sampler2D tex;\n";
-	i_data += "uniform sampler2D ShadowMap;\n";
-	i_data += "uniform sampler2D texture2;\n";
-	i_data += "uniform sampler2D texture3;\n";
-	i_data += "uniform sampler2D texture4;\n";
-	i_data += "uniform sampler2D texture5;\n";
-	i_data += "uniform sampler2D texture6;\n";
-	i_data += "uniform sampler2D texture7;\n";
-	i_data += "uniform sampler2D texture8;\n";
-
-	// timer data
-	i_data += "uniform float timer;\n";
-
-	// material types
-	i_data += "#if defined(SPECULAR)\n";
-	i_data += "#define normaltexture texture2\n";
-	i_data += "#define speculartexture texture3\n";
-	i_data += "#define brighttexture texture4\n";
-	i_data += "#define detailtexture texture5\n";
-	i_data += "#define glowtexture texture6\n";
-	i_data += "#elif defined(PBR)\n";
-	i_data += "#define normaltexture texture2\n";
-	i_data += "#define metallictexture texture3\n";
-	i_data += "#define roughnesstexture texture4\n";
-	i_data += "#define aotexture texture5\n";
-	i_data += "#define brighttexture texture6\n";
-	i_data += "#define detailtexture texture7\n";
-	i_data += "#define glowtexture texture8\n";
-	i_data += "#else\n";
-	i_data += "#define brighttexture texture2\n";
-	i_data += "#define detailtexture texture3\n";
-	i_data += "#define glowtexture texture4\n";
-	i_data += "#endif\n";
 
 #ifdef __APPLE__
 	// The noise functions are completely broken in macOS OpenGL drivers
@@ -342,6 +344,10 @@ bool FShader::Load(const char * name, const char * vert_prog_lump, const char *
 	i_data += "#define noise4(unused) vec4(0)\n";
 #endif // __APPLE__
 
+#ifdef NPOT_EMULATION
+	i_data += "#define NPOT_EMULATION\nuniform vec2 uNpotEmulation;\n";
+#endif
+
 	int vp_lump = fileSystem.CheckNumForFullName(vert_prog_lump, 0);
 	if (vp_lump == -1) I_Error("Unable to load '%s'", vert_prog_lump);
 	FileData vp_data = fileSystem.ReadFile(vp_lump);
@@ -577,6 +583,9 @@ bool FShader::Load(const char * name, const char * vert_prog_lump, const char *
 	muSplitBottomPlane.Init(hShader, "uSplitBottomPlane");
 	muSplitTopPlane.Init(hShader, "uSplitTopPlane");
 	muDetailParms.Init(hShader, "uDetailParms");
+#ifdef NPOT_EMULATION
+	muNpotEmulation.Init(hShader, "uNpotEmulation");
+#endif
 	muInterpolationFactor.Init(hShader, "uInterpolationFactor");
 	muAlphaThreshold.Init(hShader, "uAlphaThreshold");
 	muSpecularMaterial.Init(hShader, "uSpecularMaterial");
diff --git a/src/common/rendering/gl/gl_shader.h b/src/common/rendering/gl/gl_shader.h
index fef8372cd..b42e144ef 100644
--- a/src/common/rendering/gl/gl_shader.h
+++ b/src/common/rendering/gl/gl_shader.h
@@ -262,6 +262,9 @@ class FShader
 	FBufferedUniform1f muAlphaThreshold;
 	FBufferedUniform2f muSpecularMaterial;
 	FBufferedUniform1f muTimer;
+#ifdef NPOT_EMULATION
+	FBufferedUniform2f muNpotEmulation;
+#endif
 
 	int lights_index;
 	int modelmatrix_index;
diff --git a/src/common/rendering/hwrenderer/data/hw_renderstate.h b/src/common/rendering/hwrenderer/data/hw_renderstate.h
index fac9574f7..1a9964194 100644
--- a/src/common/rendering/hwrenderer/data/hw_renderstate.h
+++ b/src/common/rendering/hwrenderer/data/hw_renderstate.h
@@ -4,6 +4,7 @@
 #include "matrix.h"
 #include "hw_material.h"
 #include "texmanip.h"
+#include "version.h"
 
 struct FColormap;
 class IVertexBuffer;
@@ -198,6 +199,9 @@ struct StreamData
 	FVector4 uSplitBottomPlane;
 
 	FVector4 uDetailParms;
+#ifdef NPOT_EMULATION
+	FVector2 uNpotEmulation;
+#endif
 };
 
 class FRenderState
@@ -289,7 +293,9 @@ public:
 		mStreamData.uSplitBottomPlane = { 0.0f, 0.0f, 0.0f, 0.0f };
 		mStreamData.uDynLightColor = { 0.0f, 0.0f, 0.0f, 0.0f };
 		mStreamData.uDetailParms = { 0.0f, 0.0f, 0.0f, 0.0f };
-
+#ifdef NPOT_EMULATION
+		mStreamData.uNpotEmulation = { 0,0 };
+#endif
 		mModelMatrix.loadIdentity();
 		mTextureMatrix.loadIdentity();
 		ClearClipSplit();
@@ -472,6 +478,13 @@ public:
 		mStreamData.uAddColor = pe;
 	}
 
+	void SetNpotEmulation(float factor, float offset)
+	{
+#ifdef NPOT_EMULATION
+		mStreamData.uNpotEmulation = { offset, factor };
+#endif
+	}
+
 	void ApplyTextureManipulation(TextureManipulation* texfx)
 	{
 		if (!texfx || texfx->AddColor.a == 0)
diff --git a/src/common/rendering/vulkan/shaders/vk_shader.cpp b/src/common/rendering/vulkan/shaders/vk_shader.cpp
index 092a20e69..7f9fa9a6f 100644
--- a/src/common/rendering/vulkan/shaders/vk_shader.cpp
+++ b/src/common/rendering/vulkan/shaders/vk_shader.cpp
@@ -25,6 +25,7 @@
 #include "hw_shaderpatcher.h"
 #include "filesystem.h"
 #include "engineerrors.h"
+#include "version.h"
 #include <ShaderLang.h>
 
 VkShaderManager::VkShaderManager(VulkanDevice *device) : device(device)
@@ -162,6 +163,9 @@ static const char *shaderBindings = R"(
 		vec4 uSplitBottomPlane;
 
 		vec4 uDetailParms;
+		#ifdef NPOT_EMULATION
+		vec2 uNpotEmulation;
+		#endif
 	};
 
 	layout(set = 0, binding = 3, std140) uniform StreamUBO {
@@ -248,6 +252,7 @@ static const char *shaderBindings = R"(
 	#define uSplitTopPlane data[uDataIndex].uSplitTopPlane
 	#define uSplitBottomPlane data[uDataIndex].uSplitBottomPlane
 	#define uDetailParms data[uDataIndex].uDetailParms
+	#define uNpotEmulation data[uDataIndex].uNpotEmulation
 
 	#define SUPPORTS_SHADOWMAPS
 	#define VULKAN_COORDINATE_SYSTEM
@@ -270,6 +275,9 @@ std::unique_ptr<VulkanShader> VkShaderManager::LoadVertShader(FString shadername
 	FString code = GetTargetGlslVersion();
 	code << defines;
 	code << "\n#define MAX_STREAM_DATA " << std::to_string(MAX_STREAM_DATA).c_str() << "\n";
+#ifdef NPOT_EMULATION
+	code << "#define NPOT_EMULATION\n"
+#endif
 	code << shaderBindings;
 	if (!device->UsedDeviceFeatures.shaderClipDistance) code << "#define NO_CLIPDISTANCE_SUPPORT\n";
 	code << "#line 1\n";
diff --git a/src/rendering/hwrenderer/scene/hw_walls.cpp b/src/rendering/hwrenderer/scene/hw_walls.cpp
index 3137679be..6a2d3ea9f 100644
--- a/src/rendering/hwrenderer/scene/hw_walls.cpp
+++ b/src/rendering/hwrenderer/scene/hw_walls.cpp
@@ -175,6 +175,10 @@ static const uint8_t renderwalltotier[] =
 	side_t::mid,
 };
 
+#ifdef NPOT_EMULATION
+CVAR(Bool, hw_npottest, false, 0)
+#endif
+
 void HWWall::RenderTexturedWall(HWDrawInfo *di, FRenderState &state, int rflags)
 {
 	int tmode = state.GetTextureMode();
@@ -187,6 +191,23 @@ void HWWall::RenderTexturedWall(HWDrawInfo *di, FRenderState &state, int rflags)
 		SetGlowPlanes(state, frontsector->ceilingplane, frontsector->floorplane);
 	}
 	state.SetMaterial(texture, UF_Texture, 0, flags & 3, 0, -1);
+#ifdef NPOT_EMULATION
+	// Test code, could be reactivated as a compatibility option in the unlikely event that some old vanilla map eve needs it.
+	if (hw_npottest)
+	{
+		int32_t size = xs_CRoundToInt(texture->GetDisplayHeight());
+		int32_t size2;
+		for (size2 = 1; size2 < size; size2 += size2) {}
+		if (size == size2)
+			state.SetNpotEmulation(0.f, 0.f);
+		else
+		{
+			float xOffset = 1.f / texture->GetDisplayWidth();
+			state.SetNpotEmulation((1.f * size2) / size, xOffset);
+		}
+	}
+#endif
+
 
 	if (type == RENDERWALL_M2SNF)
 	{
@@ -274,6 +295,7 @@ void HWWall::RenderTexturedWall(HWDrawInfo *di, FRenderState &state, int rflags)
 
 		state.EnableSplit(false);
 	}
+	state.SetNpotEmulation(0.f, 0.f);
 	state.SetObjectColor(0xffffffff);
 	state.SetObjectColor2(0);
 	state.SetAddColor(0);
diff --git a/wadsrc/static/shaders/glsl/main.fp b/wadsrc/static/shaders/glsl/main.fp
index 8960103bf..048579eee 100644
--- a/wadsrc/static/shaders/glsl/main.fp
+++ b/wadsrc/static/shaders/glsl/main.fp
@@ -540,6 +540,14 @@ vec3 ApplyNormalMap(vec2 texcoord)
 
 void SetMaterialProps(inout Material material, vec2 texCoord)
 {
+#ifdef NPOT_EMULATION
+	if (uNpotEmulation.y != 0.0)
+	{
+		float period = floor(texCoord.t / uNpotEmulation.y);
+		texCoord.s += uNpotEmulation.x * floor(mod(texCoord.t, uNpotEmulation.y));
+		texCoord.t = period + mod(texCoord.t, uNpotEmulation.y);
+	}
+#endif	
 	material.Base = getTexel(texCoord.st); 
 	material.Normal = ApplyNormalMap(texCoord.st);