diff --git a/build.gradle.kts b/build.gradle.kts
index 8150c6e8..3c9dc8ee 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -19,7 +19,7 @@ kotlin.jvmToolchain {
 }
 
 tasks.withType<KotlinCompile> {
-    setJvmDefault("all-compatibility")
+    setJvmDefault("all")
     kotlinOptions {
         languageVersion = "1.6"
         apiVersion = "1.6"
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 53a52545..91e581fa 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -1,5 +1,5 @@
 [versions]
-kotlin = "1.5.10"
+kotlin = "1.6.21"
 kotlinx-coroutines = "1.5.2"
 jetbrains-annotations = "23.0.0"
 universalcraft = "406"
diff --git a/src/main/kotlin/gg/essential/elementa/components/image/ImageProvider.kt b/src/main/kotlin/gg/essential/elementa/components/image/ImageProvider.kt
index 2ec73e43..665de727 100644
--- a/src/main/kotlin/gg/essential/elementa/components/image/ImageProvider.kt
+++ b/src/main/kotlin/gg/essential/elementa/components/image/ImageProvider.kt
@@ -3,6 +3,7 @@ package gg.essential.elementa.components.image
 import gg.essential.universal.UMatrixStack
 import java.awt.Color
 
+@JvmDefaultWithCompatibility
 interface ImageProvider {
     /**
      * Render the image provided by this component with the provided attributes.
@@ -21,4 +22,4 @@ interface ImageProvider {
 
     fun drawImageCompat(matrixStack: UMatrixStack, x: Double, y: Double, width: Double, height: Double, color: Color): Unit =
         UMatrixStack.Compat.runLegacyMethod(matrixStack) { @Suppress("DEPRECATION") drawImage(x, y, width, height, color) }
-}
\ No newline at end of file
+}
diff --git a/src/main/kotlin/gg/essential/elementa/constraints/Constraint.kt b/src/main/kotlin/gg/essential/elementa/constraints/Constraint.kt
index fd263565..a55d79e2 100644
--- a/src/main/kotlin/gg/essential/elementa/constraints/Constraint.kt
+++ b/src/main/kotlin/gg/essential/elementa/constraints/Constraint.kt
@@ -15,6 +15,7 @@ import java.awt.Color
  * [T] is what this constraint deals with, for example Float for WidthConstraint
  * or Color for ColorConstraint
  */
+@JvmDefaultWithCompatibility
 interface SuperConstraint<T> {
     var cachedValue: T
     var recalculate: Boolean
@@ -54,6 +55,7 @@ interface SuperConstraint<T> {
     fun visitImpl(visitor: ConstraintVisitor, type: ConstraintType)
 }
 
+@JvmDefaultWithCompatibility
 interface GeneralConstraint : PositionConstraint, SizeConstraint {
     fun getXValue(component: UIComponent): Float
 
@@ -70,8 +72,10 @@ interface GeneralConstraint : PositionConstraint, SizeConstraint {
     override fun getRadiusImpl(component: UIComponent) = getXValue(component)
 }
 
+@JvmDefaultWithCompatibility
 interface PositionConstraint : XConstraint, YConstraint
 
+@JvmDefaultWithCompatibility
 interface XConstraint : SuperConstraint<Float> {
     fun getXPositionImpl(component: UIComponent): Float
 
@@ -79,6 +83,7 @@ interface XConstraint : SuperConstraint<Float> {
         getCachedDebuggable(component, ConstraintType.X) { getXPositionImpl(it).roundToRealPixels() }
 }
 
+@JvmDefaultWithCompatibility
 interface YConstraint : SuperConstraint<Float> {
     fun getYPositionImpl(component: UIComponent): Float
 
@@ -86,8 +91,10 @@ interface YConstraint : SuperConstraint<Float> {
         getCachedDebuggable(component, ConstraintType.Y) { getYPositionImpl(it).roundToRealPixels() }
 }
 
+@JvmDefaultWithCompatibility
 interface SizeConstraint : WidthConstraint, HeightConstraint, RadiusConstraint
 
+@JvmDefaultWithCompatibility
 interface RadiusConstraint : SuperConstraint<Float> {
     fun getRadiusImpl(component: UIComponent): Float
 
@@ -95,6 +102,7 @@ interface RadiusConstraint : SuperConstraint<Float> {
         getCachedDebuggable(component, ConstraintType.RADIUS) { getRadiusImpl(it).roundToRealPixels() }
 }
 
+@JvmDefaultWithCompatibility
 interface WidthConstraint : SuperConstraint<Float> {
     fun getWidthImpl(component: UIComponent): Float
 
@@ -102,6 +110,7 @@ interface WidthConstraint : SuperConstraint<Float> {
         getCachedDebuggable(component, ConstraintType.WIDTH) { getWidthImpl(it).roundToRealPixels() }
 }
 
+@JvmDefaultWithCompatibility
 interface HeightConstraint : SuperConstraint<Float> {
     fun getHeightImpl(component: UIComponent): Float
 
@@ -113,6 +122,7 @@ interface HeightConstraint : SuperConstraint<Float> {
     }
 }
 
+@JvmDefaultWithCompatibility
 interface ColorConstraint : SuperConstraint<Color> {
     fun getColorImpl(component: UIComponent): Color
 
@@ -120,6 +130,7 @@ interface ColorConstraint : SuperConstraint<Color> {
         getCached(component) { getColorImpl(it) }
 }
 
+@JvmDefaultWithCompatibility
 interface MasterConstraint : PositionConstraint, SizeConstraint
 
 private inline fun SuperConstraint<Float>.getCachedDebuggable(component: UIComponent, type: ConstraintType, getImpl: (UIComponent) -> Float): Float {
diff --git a/src/main/kotlin/gg/essential/elementa/font/FontProvider.kt b/src/main/kotlin/gg/essential/elementa/font/FontProvider.kt
index 9fe8c070..143ad42e 100644
--- a/src/main/kotlin/gg/essential/elementa/font/FontProvider.kt
+++ b/src/main/kotlin/gg/essential/elementa/font/FontProvider.kt
@@ -4,6 +4,7 @@ import gg.essential.elementa.constraints.SuperConstraint
 import gg.essential.universal.UMatrixStack
 import java.awt.Color
 
+@JvmDefaultWithCompatibility
 interface FontProvider : SuperConstraint<FontProvider> {
     fun getStringWidth(string: String, pointSize: Float): Float
 
@@ -53,4 +54,4 @@ interface FontProvider : SuperConstraint<FontProvider> {
     fun getShadowHeight(): Float
 
     fun getBelowLineHeight(): Float
-}
\ No newline at end of file
+}