diff --git a/src/main/java/com/jozufozu/flywheel/backend/ShaderContext.java b/src/main/java/com/jozufozu/flywheel/backend/ShaderContext.java
index c72614242..65344a93d 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/ShaderContext.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/ShaderContext.java
@@ -32,7 +32,7 @@ public abstract class ShaderContext<P extends GlProgram> {
 		Backend.log.debug("Loaded program {}", programSpec.name);
 	}
 
-	public String preProcess(ShaderLoader loader, String shaderSrc, ShaderType type) {
+	public String preProcess(ShaderLoader loader, ShaderType type, ResourceLocation shader, String shaderSrc) {
 		return shaderSrc;
 	}
 
diff --git a/src/main/java/com/jozufozu/flywheel/backend/ShaderLoader.java b/src/main/java/com/jozufozu/flywheel/backend/ShaderLoader.java
index fc357957e..bb1ed25c0 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/ShaderLoader.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/ShaderLoader.java
@@ -127,7 +127,7 @@ public class ShaderLoader {
 	public GlShader loadShader(ShaderContext<?> ctx, ResourceLocation name, ShaderType type, ShaderConstants defines) {
 		String source = shaderSource.get(name);
 
-		source = ctx.preProcess(this, source, type);
+		source = ctx.preProcess(this, type, name, source);
 		source = processIncludes(source, name);
 
 		if (defines != null)
diff --git a/src/main/java/com/jozufozu/flywheel/backend/core/WorldContext.java b/src/main/java/com/jozufozu/flywheel/backend/core/WorldContext.java
index 3febc5b2b..54797de14 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/core/WorldContext.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/core/WorldContext.java
@@ -2,6 +2,7 @@ package com.jozufozu.flywheel.backend.core;
 
 import java.util.EnumMap;
 import java.util.Map;
+import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import com.jozufozu.flywheel.backend.Backend;
@@ -18,7 +19,8 @@ import net.minecraft.util.ResourceLocation;
 
 public class WorldContext<P extends BasicProgram> extends ShaderContext<P> {
 
-	private static final Pattern builtinPattern = Pattern.compile("#flwbuiltins");
+	private static final String declaration = "#flwbuiltins";
+	private static final Pattern builtinPattern = Pattern.compile(declaration);
 
 	public static final WorldContext<BasicProgram> INSTANCE = new WorldContext<>(new ResourceLocation("create", "std"), new FogSensitiveProgram.SpecLoader<>(BasicProgram::new));
 	public static final WorldContext<CrumblingProgram> CRUMBLING = new WorldContext<>(new ResourceLocation("create", "crumbling"), new FogSensitiveProgram.SpecLoader<>(CrumblingProgram::new));
@@ -48,11 +50,15 @@ public class WorldContext<P extends BasicProgram> extends ShaderContext<P> {
 	}
 
 	@Override
-	public String preProcess(ShaderLoader loader, String shaderSrc, ShaderType type) {
+	public String preProcess(ShaderLoader loader, ShaderType type, ResourceLocation shader, String shaderSrc) {
 		String builtinSrc = loader.getShaderSource(builtins.get(type));
 
-		return builtinPattern.matcher(shaderSrc)
-				.replaceFirst(builtinSrc);
+		Matcher matcher = builtinPattern.matcher(shaderSrc);
+
+		if (matcher.find())
+			return matcher.replaceFirst(builtinSrc);
+
+		throw new RuntimeException(String.format("%s shader '%s' is missing %s, cannot use in World Context", type.name, shader, declaration));
 	}
 
 	@Override
diff --git a/src/main/java/com/jozufozu/flywheel/backend/gl/shader/ShaderType.java b/src/main/java/com/jozufozu/flywheel/backend/gl/shader/ShaderType.java
index 8f6ec6801..2ac5a3721 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/gl/shader/ShaderType.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/gl/shader/ShaderType.java
@@ -3,13 +3,15 @@ package com.jozufozu.flywheel.backend.gl.shader;
 import org.lwjgl.opengl.GL20;
 
 public enum ShaderType {
-	VERTEX(GL20.GL_VERTEX_SHADER),
-	FRAGMENT(GL20.GL_FRAGMENT_SHADER),
+	VERTEX("vertex", GL20.GL_VERTEX_SHADER),
+	FRAGMENT("fragment", GL20.GL_FRAGMENT_SHADER),
 	;
 
+	public final String name;
 	public final int glEnum;
 
-	ShaderType(int glEnum) {
+	ShaderType(String name, int glEnum) {
+		this.name = name;
 		this.glEnum = glEnum;
 	}
 }