diff --git a/src/8.guest/2020/oit/composite.fs b/src/8.guest/2020/oit/composite.fs
index ad6c655..e760c72 100644
--- a/src/8.guest/2020/oit/composite.fs
+++ b/src/8.guest/2020/oit/composite.fs
@@ -1,4 +1,4 @@
-#version 400 core
+#version 420 core
 
 // shader outputs
 layout (location = 0) out vec4 frag;
diff --git a/src/8.guest/2020/oit/composite.vs b/src/8.guest/2020/oit/composite.vs
index 87fa99c..fa50aa0 100644
--- a/src/8.guest/2020/oit/composite.vs
+++ b/src/8.guest/2020/oit/composite.vs
@@ -1,4 +1,4 @@
-#version 400 core
+#version 420 core
 
 // shader inputs
 layout (location = 0) in vec3 position;
diff --git a/src/8.guest/2020/oit/screen.fs b/src/8.guest/2020/oit/screen.fs
index af72188..4bfd77f 100644
--- a/src/8.guest/2020/oit/screen.fs
+++ b/src/8.guest/2020/oit/screen.fs
@@ -1,4 +1,4 @@
-#version 400 core
+#version 420 core
 
 // shader inputs
 in vec2 texture_coords;
diff --git a/src/8.guest/2020/oit/screen.vs b/src/8.guest/2020/oit/screen.vs
index 5bac53b..5fa72da 100644
--- a/src/8.guest/2020/oit/screen.vs
+++ b/src/8.guest/2020/oit/screen.vs
@@ -1,4 +1,4 @@
-#version 400 core
+#version 420 core
 
 // shader inputs
 layout (location = 0) in vec3 position;
diff --git a/src/8.guest/2020/oit/solid.fs b/src/8.guest/2020/oit/solid.fs
index 808f381..d7d189a 100644
--- a/src/8.guest/2020/oit/solid.fs
+++ b/src/8.guest/2020/oit/solid.fs
@@ -1,4 +1,4 @@
-#version 400 core
+#version 420 core
 
 // shader outputs
 layout (location = 0) out vec4 frag;
diff --git a/src/8.guest/2020/oit/solid.vs b/src/8.guest/2020/oit/solid.vs
index f2ee3f7..d6c2e5c 100644
--- a/src/8.guest/2020/oit/solid.vs
+++ b/src/8.guest/2020/oit/solid.vs
@@ -1,4 +1,4 @@
-#version 400 core
+#version 420 core
 
 // shader inputs
 layout (location = 0) in vec3 position;
diff --git a/src/8.guest/2020/oit/transparent.fs b/src/8.guest/2020/oit/transparent.fs
index ec8935c..9da6903 100644
--- a/src/8.guest/2020/oit/transparent.fs
+++ b/src/8.guest/2020/oit/transparent.fs
@@ -1,4 +1,4 @@
-#version 400 core
+#version 420 core
 
 // shader outputs
 layout (location = 0) out vec4 accum;
diff --git a/src/8.guest/2020/oit/transparent.vs b/src/8.guest/2020/oit/transparent.vs
index 47f879d..a846e36 100644
--- a/src/8.guest/2020/oit/transparent.vs
+++ b/src/8.guest/2020/oit/transparent.vs
@@ -1,4 +1,4 @@
-#version 400 core
+#version 420 core
 
 // shader inputs
 layout (location = 0) in vec3 position;
diff --git a/src/8.guest/2020/oit/weighted_blended.cpp b/src/8.guest/2020/oit/weighted_blended.cpp
index b382f37..66992a2 100644
--- a/src/8.guest/2020/oit/weighted_blended.cpp
+++ b/src/8.guest/2020/oit/weighted_blended.cpp
@@ -36,7 +36,7 @@ int main(int argc, char* argv[])
 	// ------------------------------
 	glfwInit();
 	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
-	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
 	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
 
 	#ifdef __APPLE__