diff --git a/src/test/fixtures/README.md b/src/test/fixtures/README.md
index 5abba95..d0b1d6c 100644
--- a/src/test/fixtures/README.md
+++ b/src/test/fixtures/README.md
@@ -87,3 +87,14 @@ Compiled with Scala 2.11.5 under Java 8, `-target:jvm-1.8`, against the referenc
 (SHA-256 `c003d02407d901271f42e182b5036ed3c295c2acbf416603513d2bec5b8210d0`). Class-file SHA-256 is
 `0b9d9dba78a25b0c0867fe545bc6c6400be272c418d755ef72f46dde6294c75e`, stored as
 `src/test/resources/compat/ReferenceScalaItemMultiPart.class.b64`.
+
+### `ReferenceScalaEdgePart`
+
+`scala/codechicken/multipart/compat/ReferenceScalaEdgePart.scala` mixes in `TEdgePart` without overriding what it
+supplies, so its compiled forwarder calls `TEdgePart$class.conductsRedstone` and its constructor calls
+`TEdgePart$class.$init$`. OpenComputers links against `$init$`.
+
+Compiled with Scala 2.11.5 under Java 8, `-target:jvm-1.8`, against the reference dev jar built at `f2f1870`
+(SHA-256 `cec40ee4c94f89fadf29e3f4860c68ca7d55caf12634d950a3eb5ecfb272a01b`). Class-file SHA-256 is
+`76e4d3875ae9246ed2277f0470b22f596885282386ed179a42e5f571711ae5e0`, stored as
+`src/test/resources/compat/ReferenceScalaEdgePart.class.b64`.
diff --git a/src/test/fixtures/scala/codechicken/multipart/compat/ReferenceScalaEdgePart.scala b/src/test/fixtures/scala/codechicken/multipart/compat/ReferenceScalaEdgePart.scala
new file mode 100644
index 0000000..888d4ca
--- /dev/null
+++ b/src/test/fixtures/scala/codechicken/multipart/compat/ReferenceScalaEdgePart.scala
@@ -0,0 +1,12 @@
+package codechicken.multipart.compat
+
+import codechicken.multipart.{TEdgePart, TMultiPart}
+
+/** Mixes in TEdgePart without overriding what it supplies, so the compiled forwarder calls
+  * TEdgePart$class.conductsRedstone and the constructor calls TEdgePart$class.$init$.
+  */
+class ReferenceScalaEdgePart extends TMultiPart with TEdgePart {
+  def getType = "test:reference-edge"
+
+  def getSlotMask = 1 << 15
+}
diff --git a/src/test/java/codechicken/multipart/EdgePartCharacterizationTest.java b/src/test/java/codechicken/multipart/EdgePartCharacterizationTest.java
new file mode 100644
index 0000000..6d1b864
--- /dev/null
+++ b/src/test/java/codechicken/multipart/EdgePartCharacterizationTest.java
@@ -0,0 +1,58 @@
+package codechicken.multipart;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+class EdgePartCharacterizationTest {
+
+    @Test
+    void edgePartsDoNotConductRedstoneByDefault() {
+        assertFalse(new ForwardingPart().conductsRedstone());
+    }
+
+    /** The bridge holds the trait default rather than dispatching, so an override does not change what it returns. */
+    @Test
+    void deprecatedBridgeReturnsTheTraitDefaultEvenWhenOverridden() {
+        assertFalse(TEdgePart$class.conductsRedstone(new ForwardingPart()));
+        assertTrue(new ConductingPart().conductsRedstone());
+        assertFalse(TEdgePart$class.conductsRedstone(new ConductingPart()));
+    }
+
+    @Test
+    void edgePartIsASlottedPart() {
+        ForwardingPart part = new ForwardingPart();
+
+        assertTrue(part instanceof TSlottedPart);
+        assertEquals(1 << 15, part.getSlotMask());
+    }
+
+    /** Mirrors the forwarder Scala emits for a class mixing in the trait without overriding it. */
+    private static class ForwardingPart extends TMultiPart implements TEdgePart {
+
+        @Override
+        public String getType() {
+            return "test:edge";
+        }
+
+        @Override
+        public int getSlotMask() {
+            return 1 << 15;
+        }
+
+        @Override
+        public boolean conductsRedstone() {
+            return TEdgePart$class.conductsRedstone(this);
+        }
+    }
+
+    private static final class ConductingPart extends ForwardingPart {
+
+        @Override
+        public boolean conductsRedstone() {
+            return true;
+        }
+    }
+}
diff --git a/src/test/java/codechicken/multipart/TEdgePartBinaryCompatibilityTest.java b/src/test/java/codechicken/multipart/TEdgePartBinaryCompatibilityTest.java
new file mode 100644
index 0000000..87b4c7a
--- /dev/null
+++ b/src/test/java/codechicken/multipart/TEdgePartBinaryCompatibilityTest.java
@@ -0,0 +1,53 @@
+package codechicken.multipart;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.Base64;
+import java.util.Objects;
+import java.util.Scanner;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Loads a Scala class compiled against the reference dev jar, whose forwarder calls TEdgePart$class.conductsRedstone
+ * and whose constructor calls TEdgePart$class.$init$. OpenComputers links against the latter.
+ */
+class TEdgePartBinaryCompatibilityTest {
+
+    @Test
+    void referenceScalaImplementorStillLinksThroughTheBridge() throws Exception {
+        Class<?> fixtureClass = new FixtureClassLoader(TEdgePart.class.getClassLoader()).define(loadFixture());
+        Object fixture = fixtureClass.getDeclaredConstructor().newInstance();
+
+        assertTrue(fixture instanceof TEdgePart);
+        assertTrue(fixture instanceof TSlottedPart);
+        assertTrue(fixture instanceof TMultiPart);
+        TEdgePart part = (TEdgePart) fixture;
+
+        assertFalse(part.conductsRedstone());
+        assertEquals(1 << 15, part.getSlotMask());
+    }
+
+    private static byte[] loadFixture() {
+        InputStream input = Objects.requireNonNull(
+                TEdgePartBinaryCompatibilityTest.class.getResourceAsStream("/compat/ReferenceScalaEdgePart.class.b64"));
+        try (Scanner scanner = new Scanner(input, StandardCharsets.US_ASCII.name()).useDelimiter("\\A")) {
+            return Base64.getMimeDecoder().decode(scanner.next());
+        }
+    }
+
+    private static final class FixtureClassLoader extends ClassLoader {
+
+        private FixtureClassLoader(ClassLoader parent) {
+            super(parent);
+        }
+
+        private Class<?> define(byte[] bytecode) {
+            return defineClass(null, bytecode, 0, bytecode.length);
+        }
+    }
+}
diff --git a/src/test/resources/compat/ReferenceScalaEdgePart.class.b64 b/src/test/resources/compat/ReferenceScalaEdgePart.class.b64
new file mode 100644
index 0000000..a43b0ca
--- /dev/null
+++ b/src/test/resources/compat/ReferenceScalaEdgePart.class.b64
@@ -0,0 +1,22 @@
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