diff --git a/lynglib/src/commonMain/kotlin/net/sergeych/lyng/Script.kt b/lynglib/src/commonMain/kotlin/net/sergeych/lyng/Script.kt
index 155643c..1648184 100644
--- a/lynglib/src/commonMain/kotlin/net/sergeych/lyng/Script.kt
+++ b/lynglib/src/commonMain/kotlin/net/sergeych/lyng/Script.kt
@@ -875,6 +875,7 @@ class Script(
                 }
                 addPackage("lyng.complex") { module ->
                     module.eval(Source("lyng.complex", complexLyng))
+                    ObjComplexSupport.bindTo(module)
                 }
                 addPackage("lyng.buffer") {
                     it.addConstDoc(
diff --git a/lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjComplexSupport.kt b/lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjComplexSupport.kt
new file mode 100644
index 0000000..dde3bb6
--- /dev/null
+++ b/lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjComplexSupport.kt
@@ -0,0 +1,99 @@
+/*
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package net.sergeych.lyng.obj
+
+import net.sergeych.lyng.*
+import net.sergeych.lyng.miniast.addPropertyDoc
+import net.sergeych.lyng.miniast.type
+import net.sergeych.lyng.requiredArg
+
+object ObjComplexSupport {
+    private object BoundMarker
+    private val complexTypeDecl = TypeDecl.Simple("lyng.complex.Complex", false)
+
+    suspend fun bindTo(module: ModuleScope) {
+        val complexClass = module.requireClass("Complex")
+        if (complexClass.kotlinClassData === BoundMarker) return
+        complexClass.kotlinClassData = BoundMarker
+
+        val decimalModule = module.currentImportProvider.createModuleScope(module.pos, "lyng.decimal")
+        val decimalClass = decimalModule.requireClass("Decimal")
+
+        decimalClass.addPropertyDoc(
+            name = "re",
+            doc = "Convert this Decimal to a Complex with zero imaginary part.",
+            type = type("lyng.complex.Complex"),
+            moduleName = "lyng.complex",
+            getter = {
+                newComplex(
+                    complexClass,
+                    decimalToReal(thisObj),
+                    0.0
+                )
+            }
+        )
+        decimalClass.members["re"] = decimalClass.members.getValue("re").copy(typeDecl = complexTypeDecl)
+
+        decimalClass.addPropertyDoc(
+            name = "i",
+            doc = "Convert this Decimal to a pure imaginary Complex after rounding to Real.",
+            type = type("lyng.complex.Complex"),
+            moduleName = "lyng.complex",
+            getter = {
+                newComplex(
+                    complexClass,
+                    0.0,
+                    decimalToReal(thisObj)
+                )
+            }
+        )
+        decimalClass.members["i"] = decimalClass.members.getValue("i").copy(typeDecl = complexTypeDecl)
+
+        OperatorInteropRegistry.register(
+            leftClass = decimalClass,
+            rightClass = complexClass,
+            commonClass = complexClass,
+            operatorNames = listOf(
+                InteropOperator.Plus.name,
+                InteropOperator.Minus.name,
+                InteropOperator.Mul.name,
+                InteropOperator.Div.name
+            ),
+            leftToCommon = ObjExternCallable.fromBridge {
+                newComplex(
+                    complexClass,
+                    decimalToReal(requiredArg(0)),
+                    0.0
+                )
+            },
+            rightToCommon = ObjExternCallable.fromBridge {
+                requiredArg<Obj>(0)
+            }
+        )
+    }
+
+    private suspend fun ScopeFacade.newComplex(complexClass: ObjClass, real: Double, imag: Double): ObjInstance =
+        call(
+            complexClass,
+            Arguments(ObjReal.of(real), ObjReal.of(imag))
+        ) as? ObjInstance ?: raiseIllegalState("Complex() did not return an object instance")
+
+    private fun ScopeFacade.decimalToReal(value: Obj): Double =
+        ObjDecimalSupport.toDoubleOrNull(value)
+            ?: raiseClassCastError("expected Decimal-compatible value, got ${value.objClass.className}")
+}
diff --git a/lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjDecimalSupport.kt b/lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjDecimalSupport.kt
index f15d9fa..cda492a 100644
--- a/lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjDecimalSupport.kt
+++ b/lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjDecimalSupport.kt
@@ -54,16 +54,20 @@ object ObjDecimalSupport {
             instance.kotlinInstanceData = zero
         }
         decimalClass.addFn("plus") {
-            newInstance(decimalClass, valueOf(thisObj).plus(coerceArg(requireScope(), args.firstAndOnly())))
+            OperatorInteropRegistry.invokeBinary(requireScope(), thisObj, args.firstAndOnly(), InteropOperator.Plus)
+                ?: newInstance(decimalClass, valueOf(thisObj).plus(coerceArg(requireScope(), args.firstAndOnly())))
         }
         decimalClass.addFn("minus") {
-            newInstance(decimalClass, valueOf(thisObj).minus(coerceArg(requireScope(), args.firstAndOnly())))
+            OperatorInteropRegistry.invokeBinary(requireScope(), thisObj, args.firstAndOnly(), InteropOperator.Minus)
+                ?: newInstance(decimalClass, valueOf(thisObj).minus(coerceArg(requireScope(), args.firstAndOnly())))
         }
         decimalClass.addFn("mul") {
-            newInstance(decimalClass, valueOf(thisObj).times(coerceArg(requireScope(), args.firstAndOnly())))
+            OperatorInteropRegistry.invokeBinary(requireScope(), thisObj, args.firstAndOnly(), InteropOperator.Mul)
+                ?: newInstance(decimalClass, valueOf(thisObj).times(coerceArg(requireScope(), args.firstAndOnly())))
         }
         decimalClass.addFn("div") {
-            newInstance(decimalClass, divideWithContext(valueOf(thisObj), coerceArg(requireScope(), args.firstAndOnly()), currentDivisionMode(requireScope())))
+            OperatorInteropRegistry.invokeBinary(requireScope(), thisObj, args.firstAndOnly(), InteropOperator.Div)
+                ?: newInstance(decimalClass, divideWithContext(valueOf(thisObj), coerceArg(requireScope(), args.firstAndOnly()), currentDivisionMode(requireScope())))
         }
         decimalClass.addFn("mod") {
             newInstance(decimalClass, valueOf(thisObj).rem(coerceArg(requireScope(), args.firstAndOnly())))
diff --git a/lynglib/src/commonTest/kotlin/net/sergeych/lyng/ComplexModuleTest.kt b/lynglib/src/commonTest/kotlin/net/sergeych/lyng/ComplexModuleTest.kt
index 4d7e1ab..43f7da9 100644
--- a/lynglib/src/commonTest/kotlin/net/sergeych/lyng/ComplexModuleTest.kt
+++ b/lynglib/src/commonTest/kotlin/net/sergeych/lyng/ComplexModuleTest.kt
@@ -73,4 +73,32 @@ class ComplexModuleTest {
             """.trimIndent()
         )
     }
+
+    @Test
+    fun testInferences() = runTest {
+        eval(
+            $$"""
+            import lyng.decimal
+            import lyng.complex
+            
+            assert( 1.i is Complex )
+            assert( 5 + 1.i is Complex )
+        """.trimIndent()
+        )
+    }
+    @Test
+    fun testDecimalInferences() = runTest {
+        eval(
+            $$"""
+            import lyng.decimal
+            import lyng.complex
+            
+            assert( 1.d.i is Complex )
+            assert( 5 + 1.d.i is Complex )
+            assert( 5.d + 1.i is Complex )
+            assert( 5.d + 2.d.i is Complex )
+        """.trimIndent()
+        )
+    }
+
 }