diff --git a/src/net/torvald/terrarum/Hq2x.kt b/src/net/torvald/terrarum/Hq2x.kt
index ed07b69bc..e24306657 100644
--- a/src/net/torvald/terrarum/Hq2x.kt
+++ b/src/net/torvald/terrarum/Hq2x.kt
@@ -47,7 +47,7 @@ class Hq2x : Disposable {
         program = compileShader(
             Gdx.files.classpath("shaders/hq2x.vert"),
             Gdx.files.classpath("shaders/hq2x.frag"),
-            "#define SCALE ${scaleFactor}.0")
+            "")
 
         lutTexture = Texture(Gdx.files.classpath("shaders/hq${scaleFactor}x.png"))
 
diff --git a/src/shaders/hq2x.frag b/src/shaders/hq2x.frag
index 1a8361bc7..7db8dac50 100644
--- a/src/shaders/hq2x.frag
+++ b/src/shaders/hq2x.frag
@@ -1,6 +1,8 @@
+#version 150
 // This float value should be defined from the compiling code.
 // #define SCALE [2, 3, 4].0
 
+#define SCALE 2.0
 #ifdef GL_ES
 #define PRECISION mediump
 precision PRECISION float;
@@ -13,12 +15,14 @@ uniform sampler2D u_texture;
 uniform sampler2D u_lut;
 uniform vec2 u_textureSize;
 
-varying vec4 v_texCoord[4];
+in vec4 v_texCoord[4];
 
 const mat3 YUV_MATRIX = mat3(0.299, 0.587, 0.114, -0.169, -0.331, 0.5, 0.5, -0.419, -0.081);
 const vec3 YUV_THRESHOLD = vec3(48.0/255.0, 7.0/255.0, 6.0/255.0);
 const vec3 YUV_OFFSET = vec3(0, 0.5, 0.5);
 
+out vec4 fragColor;
+
 bool diff(vec3 yuv1, vec3 yuv2) {
     return any(greaterThan(abs((yuv1 + YUV_OFFSET) - (yuv2 + YUV_OFFSET)), YUV_THRESHOLD));
 }
@@ -79,5 +83,5 @@ void main() {
     float sum = dot(weights, vec4(1));
     vec3 res = (pixels * (weights / sum)).rgb;
 
-    gl_FragColor.rgb = res;
+    fragColor.rgb = res;
 }
\ No newline at end of file
diff --git a/src/shaders/hq2x.vert b/src/shaders/hq2x.vert
index 997648c3c..64fd28d1d 100644
--- a/src/shaders/hq2x.vert
+++ b/src/shaders/hq2x.vert
@@ -1,17 +1,11 @@
-#ifdef GL_ES
-#define PRECISION mediump
-precision PRECISION float;
-precision PRECISION int;
-#else
-#define PRECISION
-#endif
+#version 150
 
-attribute vec4 a_position;
-attribute vec2 a_texCoord0;
+in vec4 a_position;
+in vec2 a_texCoord0;
 
 uniform vec2 u_textureSize;
 
-varying vec4 v_texCoord[4];
+out vec4 v_texCoord[4];
 
 void main() {
     gl_Position = a_position;