diff --git a/kotlin/src/main/java/com/squareup/moshi/kotlin/KotlinJsonAdapter.kt b/kotlin/src/main/java/com/squareup/moshi/kotlin/KotlinJsonAdapter.kt
index b50a8c1..048011b 100644
--- a/kotlin/src/main/java/com/squareup/moshi/kotlin/KotlinJsonAdapter.kt
+++ b/kotlin/src/main/java/com/squareup/moshi/kotlin/KotlinJsonAdapter.kt
@@ -206,6 +206,11 @@ class KotlinJsonAdapterFactory : JsonAdapter.Factory {
         continue
       }
 
+      if (parameter != null && parameter.type != property.returnType) {
+        throw IllegalArgumentException("'${property.name}' has a constructor parameter of type " +
+            "${parameter.type} but a property of type ${property.returnType}.")
+      }
+
       if (property !is KMutableProperty1 && parameter == null) continue
 
       property.isAccessible = true
diff --git a/kotlin/src/test/java/com/squareup/moshi/kotlin/KotlinJsonAdapterTest.kt b/kotlin/src/test/java/com/squareup/moshi/kotlin/KotlinJsonAdapterTest.kt
index e25f23b..3d896e7 100644
--- a/kotlin/src/test/java/com/squareup/moshi/kotlin/KotlinJsonAdapterTest.kt
+++ b/kotlin/src/test/java/com/squareup/moshi/kotlin/KotlinJsonAdapterTest.kt
@@ -346,6 +346,21 @@ class KotlinJsonAdapterTest {
     var b: Int = -1
   }
 
+  @Test fun constructorParametersAndPropertiesWithSameNamesMustHaveSameTypes() {
+    val moshi = Moshi.Builder().add(KotlinJsonAdapterFactory()).build()
+    try {
+      moshi.adapter(ConstructorParameterWithSameNameAsPropertyButDifferentType::class.java)
+      fail()
+    } catch (expected: IllegalArgumentException) {
+      assertThat(expected).hasMessage("'a' has a constructor parameter of type " +
+          "kotlin.Int but a property of type kotlin.String.")
+    }
+  }
+
+  class ConstructorParameterWithSameNameAsPropertyButDifferentType(a: Int) {
+    var a = "boo"
+  }
+
   @Test fun supertypeConstructorParameters() {
     val moshi = Moshi.Builder().add(KotlinJsonAdapterFactory()).build()
     val jsonAdapter = moshi.adapter(SubtypeConstructorParameters::class.java)