diff --git a/src/common/engine/startupinfo.h b/src/common/engine/startupinfo.h
index 9cf9724fd..5054a4507 100644
--- a/src/common/engine/startupinfo.h
+++ b/src/common/engine/startupinfo.h
@@ -12,7 +12,7 @@ struct FStartupInfo
 	int Type;
 	int LoadLights = -1;
 	int LoadBrightmaps = -1;
-	int modern = -1;
+	int modern = 0;
 	enum
 	{
 		DefaultStartup,
diff --git a/src/common/textures/gametexture.cpp b/src/common/textures/gametexture.cpp
index d47ffb733..e4e1ac6b2 100644
--- a/src/common/textures/gametexture.cpp
+++ b/src/common/textures/gametexture.cpp
@@ -149,6 +149,7 @@ void FGameTexture::AddAutoMaterials()
 	{ "materials/ao/", &FGameTexture::AmbientOcclusion }
 	};
 
+	if (flags & GTexf_AutoMaterialsAdded) return; // do this only once
 
 	bool fullname = !!(flags & GTexf_FullNameTexture);
 	FString searchname = GetName();
@@ -177,6 +178,7 @@ void FGameTexture::AddAutoMaterials()
 			}
 		}
 	}
+	flags |= GTexf_AutoMaterialsAdded;
 }
 
 //===========================================================================
diff --git a/src/common/textures/gametexture.h b/src/common/textures/gametexture.h
index 32a2e40be..e6b3461cf 100644
--- a/src/common/textures/gametexture.h
+++ b/src/common/textures/gametexture.h
@@ -57,12 +57,14 @@ enum EGameTexFlags
 	GTexf_RenderFullbright = 32,			// always draw fullbright
 	GTexf_DisableFullbrightSprites = 64,	// This texture will not be displayed as fullbright sprite
 	GTexf_BrightmapChecked = 128,			// Check for a colormap-based brightmap was already done.
+	GTexf_AutoMaterialsAdded = 256,			// AddAutoMaterials has been called on this texture.
 };
 
 // Refactoring helper to allow piece by piece adjustment of the API
 class FGameTexture
 {
 	friend class FMaterial;
+	friend class GLDefsParser;	// this needs access to set up the texture properly
 
 	// Material layers. These are shared so reference counting is used.
 	RefCountedPtr<FTexture> Base;
diff --git a/src/common/textures/hw_material.cpp b/src/common/textures/hw_material.cpp
index af4bc2c60..c4a1ba9d3 100644
--- a/src/common/textures/hw_material.cpp
+++ b/src/common/textures/hw_material.cpp
@@ -114,7 +114,7 @@ FMaterial::FMaterial(FGameTexture * tx, int scaleflags)
 		if (index >= FIRST_USER_SHADER)
 		{
 			const UserShaderDesc &usershader = usershaders[index - FIRST_USER_SHADER];
-			//if (usershader.shaderType == mShaderIndex) // Only apply user shader if it matches the expected material
+			if (usershader.shaderType == mShaderIndex) // Only apply user shader if it matches the expected material
 			{
 				for (auto &texture : tx->CustomShaderTextures)
 				{
diff --git a/src/r_data/gldefs.cpp b/src/r_data/gldefs.cpp
index b561000c4..44467244d 100644
--- a/src/r_data/gldefs.cpp
+++ b/src/r_data/gldefs.cpp
@@ -1216,6 +1216,7 @@ class GLDefsParser
 		{
 			sc.ScriptMessage("Material definition refers nonexistent texture '%s'\n", sc.String);
 		}
+		else tex->AddAutoMaterials();	// We need these before setting up the texture.
 
 		sc.MustGetToken('{');
 		while (!sc.CheckToken('}'))
@@ -1242,14 +1243,12 @@ class GLDefsParser
 			else if (sc.Compare("glossiness"))
 			{
 				sc.MustGetFloat();
-				if (tex)
-					mlay.Glossiness = (float)sc.Float;
+				mlay.Glossiness = (float)sc.Float;
 			}
 			else if (sc.Compare("specularlevel"))
 			{
 				sc.MustGetFloat();
-				if (tex)
-					mlay.SpecularLevel = (float)sc.Float;
+				mlay.SpecularLevel = (float)sc.Float;
 			}
 			else if (sc.Compare("speed"))
 			{
@@ -1367,12 +1366,12 @@ class GLDefsParser
 		if (usershader.shader.IsNotEmpty())
 		{
 			int firstUserTexture;
-			if (mlay.Normal && mlay.Specular)
+			if ((mlay.Normal || tex->Normal.get()) && (mlay.Specular || tex->Specular.get()))
 			{
 				usershader.shaderType = SHADER_Specular;
 				firstUserTexture = 7;
 			}
-			else if (mlay.Normal && mlay.Metallic && mlay.Roughness && mlay.AmbientOcclusion)
+			else if ((mlay.Normal || tex->Normal.get()) && (mlay.Metallic || tex->Metallic.get()) && (mlay.Roughness || tex->Roughness.get()) && (mlay.AmbientOcclusion || tex->AmbientOcclusion.get()))
 			{
 				usershader.shaderType = SHADER_PBR;
 				firstUserTexture = 9;
@@ -1523,6 +1522,7 @@ class GLDefsParser
 			sc.MustGetString();
 			FTextureID no = TexMan.CheckForTexture(sc.String, type);
 			auto tex = TexMan.GetGameTexture(no);
+			if (tex) tex->AddAutoMaterials();
 			MaterialLayers mlay = { -1000, -1000 };
 
 			sc.MustGetToken('{');