diff --git a/fabric/src/main/java/net/deechael/concentration/fabric/mixin/GLFWMixin.java b/fabric/src/main/java/net/deechael/concentration/fabric/mixin/GLFWMixin.java
index 4bcc019..0b4c346 100644
--- a/fabric/src/main/java/net/deechael/concentration/fabric/mixin/GLFWMixin.java
+++ b/fabric/src/main/java/net/deechael/concentration/fabric/mixin/GLFWMixin.java
@@ -76,14 +76,14 @@ public class GLFWMixin {
             } else {
                 ConcentrationConstants.LOGGER.info("Trying to switch to borderless fullscreen mode");
 
-                /*if (ConcentrationConfigFabric.getInstance().customized) {
+                if (ConcentrationConfigFabric.getInstance().customized) {
                     ConcentrationConstants.LOGGER.info("Customization enabled, so replace the fullscreen size with customized size");
+                    finalMonitor = 0L;
                     finalX = config.x + (config.related ? monitorInstance.getX() : 0);
                     finalY = config.y - (config.height == height ? 1 : 0) + (config.related ? monitorInstance.getY() : 0);
                     finalWidth = config.width;
                     finalHeight = config.height + (config.height == height ? 1 : 0);
-                } else */
-                {
+                } else {
                     finalMonitor = monitor;
                     finalX = monitorInstance.getX();
                     finalY = monitorInstance.getY();
@@ -165,6 +165,12 @@ public class GLFWMixin {
                     }
                 }
             }
+        } else {
+            if (windowInstance.isFullscreen() && Config.isBorderless() && Config.isCustomized()) {
+                GLFW.glfwSetWindowAttrib(window, GLFW.GLFW_DECORATED, GLFW.GLFW_FALSE);
+            } else {
+                GLFW.glfwSetWindowAttrib(window, GLFW.GLFW_DECORATED, GLFW.GLFW_TRUE);
+            }
         }
 
         ConcentrationConstants.LOGGER.info("================= [Concentration End] =================");
diff --git a/fabric/src/main/java/net/deechael/concentration/fabric/mixin/WindowMixin.java b/fabric/src/main/java/net/deechael/concentration/fabric/mixin/WindowMixin.java
index abf9541..1bb4000 100644
--- a/fabric/src/main/java/net/deechael/concentration/fabric/mixin/WindowMixin.java
+++ b/fabric/src/main/java/net/deechael/concentration/fabric/mixin/WindowMixin.java
@@ -48,6 +48,8 @@ public abstract class WindowMixin {
     @Final
     private long window;
 
+    @Shadow public abstract boolean isFullscreen();
+
     @Inject(method = "onMove", at = @At("HEAD"))
     private void inject$onMove$head(long window, int x, int y, CallbackInfo ci) {
         if (!this.fullscreen) {
@@ -114,16 +116,15 @@ public abstract class WindowMixin {
             } else {
                 ConcentrationConstants.LOGGER.info("Trying to switch to borderless fullscreen mode");
 
-                /*if (ConcentrationConfigFabric.getInstance().customized) {
-                    GLFW.glfwSetWindowAttrib(window, GLFW.GLFW_DECORATED, GLFW.GLFW_FALSE);
-                    finalMonitor = 0L;
+                if (ConcentrationConfigFabric.getInstance().customized) {
                     ConcentrationConstants.LOGGER.info("Customization enabled, so replace the fullscreen size with customized size");
+
+                    finalMonitor = 0L;
                     finalX = config.x + (config.related ? monitorInstance.getX() : 0);
                     finalY = config.y - (config.height == height ? 1 : 0) + (config.related ? monitorInstance.getY() : 0);
                     finalWidth = config.width;
                     finalHeight = config.height + (config.height == height ? 1 : 0);
-                } else */
-                {
+                } else {
                     finalMonitor = monitor;
                     finalX = monitorInstance.getX();
                     finalY = monitorInstance.getY();
@@ -166,6 +167,7 @@ public abstract class WindowMixin {
         GLFW.glfwSetWindowMonitor(window, finalMonitor, finalX, finalY, finalWidth, finalHeight, -1);
 
         if (this.fullscreen && !(Config.isBorderless() && Config.isCustomized())) {
+            GLFW.glfwSetWindowAttrib(window, GLFW.GLFW_DECORATED, GLFW.GLFW_TRUE);
             GLFW.glfwSetWindowAttrib(this.window, 0x20006, 1);
 
             long hWnd = GLFWNativeWin32.glfwGetWin32Window(this.window);
@@ -186,6 +188,12 @@ public abstract class WindowMixin {
                     }
                 }
             }
+        } else {
+            if (this.isFullscreen() && Config.isBorderless() && Config.isCustomized()) {
+                GLFW.glfwSetWindowAttrib(window, GLFW.GLFW_DECORATED, GLFW.GLFW_FALSE);
+            } else {
+                GLFW.glfwSetWindowAttrib(window, GLFW.GLFW_DECORATED, GLFW.GLFW_TRUE);
+            }
         }
 
         ConcentrationConstants.LOGGER.info("================= [Concentration End] =================");
diff --git a/forge/src/main/java/net/deechael/concentration/forge/mixin/WindowMixin.java b/forge/src/main/java/net/deechael/concentration/forge/mixin/WindowMixin.java
index 220bbd4..4e5a04f 100644
--- a/forge/src/main/java/net/deechael/concentration/forge/mixin/WindowMixin.java
+++ b/forge/src/main/java/net/deechael/concentration/forge/mixin/WindowMixin.java
@@ -47,6 +47,10 @@ public abstract class WindowMixin {
     @Shadow
     @Final
     private long window;
+
+    @Shadow
+    public abstract boolean isFullscreen();
+
     @Unique
     private long concentration$lastMonitor = -1;
 
@@ -131,7 +135,7 @@ public abstract class WindowMixin {
             } else {
                 ConcentrationConstants.LOGGER.info("Trying to switch to borderless fullscreen mode");
 
-                /*if (ConcentrationConfigForge.CUSTOMIZED.get()) {
+                if (ConcentrationConfigForge.CUSTOMIZED.get()) {
                     final boolean related = ConcentrationConfigForge.RELATED.get();
                     final int configX = ConcentrationConfigForge.X.get();
                     final int configY = ConcentrationConfigForge.Y.get();
@@ -140,12 +144,12 @@ public abstract class WindowMixin {
 
                     ConcentrationConstants.LOGGER.info("Customization enabled, so replace the fullscreen size with customized size");
 
+                    finalMonitor = 0L;
                     finalX = configX + (related ? monitorInstance.getX() : 0);
                     finalY = configY - (configHeight == height ? 1 : 0) + (related ? monitorInstance.getY() : 0);
                     finalWidth = configWidth;
                     finalHeight = configHeight + (configHeight == height ? 1 : 0);
-                } else */
-                {
+                } else {
                     finalMonitor = monitor;
                     finalX = monitorInstance.getX();
                     finalY = monitorInstance.getY();
@@ -208,6 +212,12 @@ public abstract class WindowMixin {
                     }
                 }
             }
+        } else {
+            if (this.isFullscreen() && Config.isBorderless() && Config.isCustomized()) {
+                GLFW.glfwSetWindowAttrib(window, GLFW.GLFW_DECORATED, GLFW.GLFW_FALSE);
+            } else {
+                GLFW.glfwSetWindowAttrib(window, GLFW.GLFW_DECORATED, GLFW.GLFW_TRUE);
+            }
         }
 
         ConcentrationConstants.LOGGER.info("================= [Concentration End] =================");
diff --git a/neoforge/src/main/java/net/deechael/concentration/neoforge/mixin/WindowMixin.java b/neoforge/src/main/java/net/deechael/concentration/neoforge/mixin/WindowMixin.java
index d19ca40..3c1b08f 100644
--- a/neoforge/src/main/java/net/deechael/concentration/neoforge/mixin/WindowMixin.java
+++ b/neoforge/src/main/java/net/deechael/concentration/neoforge/mixin/WindowMixin.java
@@ -47,6 +47,10 @@ public abstract class WindowMixin {
     @Shadow
     @Final
     private long window;
+
+    @Shadow
+    public abstract boolean isFullscreen();
+
     @Unique
     private long concentration$lastMonitor = -1;
 
@@ -131,21 +135,21 @@ public abstract class WindowMixin {
             } else {
                 ConcentrationConstants.LOGGER.info("Trying to switch to borderless fullscreen mode");
 
-                /*if (ConcentrationConfigForge.CUSTOMIZED.get()) {
-                    final boolean related = ConcentrationConfigForge.RELATED.get();
-                    final int configX = ConcentrationConfigForge.X.get();
-                    final int configY = ConcentrationConfigForge.Y.get();
-                    final int configWidth = ConcentrationConfigForge.WIDTH.get();
-                    final int configHeight = ConcentrationConfigForge.HEIGHT.get();
+                if (ConcentrationConfigNeoForge.CUSTOMIZED.get()) {
+                    final boolean related = ConcentrationConfigNeoForge.RELATED.get();
+                    final int configX = ConcentrationConfigNeoForge.X.get();
+                    final int configY = ConcentrationConfigNeoForge.Y.get();
+                    final int configWidth = ConcentrationConfigNeoForge.WIDTH.get();
+                    final int configHeight = ConcentrationConfigNeoForge.HEIGHT.get();
 
                     ConcentrationConstants.LOGGER.info("Customization enabled, so replace the fullscreen size with customized size");
 
+                    finalMonitor = 0L;
                     finalX = configX + (related ? monitorInstance.getX() : 0);
                     finalY = configY - (configHeight == height ? 1 : 0) + (related ? monitorInstance.getY() : 0);
                     finalWidth = configWidth;
                     finalHeight = configHeight + (configHeight == height ? 1 : 0);
-                } else */
-                {
+                } else {
                     finalMonitor = monitor;
                     finalX = monitorInstance.getX();
                     finalY = monitorInstance.getY();
@@ -208,6 +212,12 @@ public abstract class WindowMixin {
                     }
                 }
             }
+        } else {
+            if (this.isFullscreen() && Config.isBorderless() && Config.isCustomized()) {
+                GLFW.glfwSetWindowAttrib(window, GLFW.GLFW_DECORATED, GLFW.GLFW_FALSE);
+            } else {
+                GLFW.glfwSetWindowAttrib(window, GLFW.GLFW_DECORATED, GLFW.GLFW_TRUE);
+            }
         }
 
         ConcentrationConstants.LOGGER.info("================= [Concentration End] =================");