diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/signature/IdSignatureBuilder.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/signature/IdSignatureBuilder.kt
index 7a0b0d99235..0e644b6f6d0 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/signature/IdSignatureBuilder.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/signature/IdSignatureBuilder.kt
@@ -13,13 +13,50 @@ import org.jetbrains.kotlin.name.FqName
 abstract class IdSignatureBuilder<Declaration : Any, Mangler : KotlinMangler<Declaration>> {
     protected var packageFqn: FqName = FqName.ROOT
     protected val classFqnSegments = mutableListOf<String>()
+
+    /**
+     * Use [setHashIdAndDescriptionFor] or [setHashIdAndDescription] with `isPropertyAccessor = false` to set this property.
+     *
+     * This property is made private to enforce always setting [description] along with it.
+     */
     private var hashId: Long? = null
+
+    /**
+     * Use [setHashIdAndDescriptionFor] or [setHashIdAndDescription] with `isPropertyAccessor = true` to set this property.
+     *
+     * This property is made private to enforce always setting [description] along with it.
+     */
     private var hashIdAcc: Long? = null
+
     protected var overridden: List<Declaration>? = null
     protected var mask = 0L
+
+    /**
+     * For local or top-level private declarations, the signature of the containing declaration **or** [IdSignature.FileSignature]
+     * respectively.
+     *
+     * Used to build [IdSignature.CompositeSignature].
+     */
     protected var container: IdSignature? = null
+
+    protected fun createContainer() {
+        container = container?.let {
+            buildContainerSignature(it)
+        } ?: build()
+
+        reset(false)
+    }
+
     protected var description: String? = null
 
+    protected abstract fun renderDeclarationForDescription(declaration: Declaration): String
+
+    protected fun setDescriptionIfLocalDeclaration(declaration: Declaration) {
+        if (container != null) {
+            description = renderDeclarationForDescription(declaration)
+        }
+    }
+
     protected var isTopLevelPrivate: Boolean = false
 
     protected abstract val currentFileSignature: IdSignature.FileSignature?
@@ -59,7 +96,7 @@ abstract class IdSignatureBuilder<Declaration : Any, Mangler : KotlinMangler<Dec
     }
 
 
-    protected fun buildContainerSignature(container: IdSignature): IdSignature.CompositeSignature {
+    private fun buildContainerSignature(container: IdSignature): IdSignature.CompositeSignature {
         val localName = classFqnSegments.joinToString(".")
         val localHash = hashId
         return IdSignature.CompositeSignature(container, IdSignature.LocalSignature(localName, localHash, description))
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/signature/IdSignatureDescriptor.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/signature/IdSignatureDescriptor.kt
index e6e942a3b68..fd85ec172f5 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/signature/IdSignatureDescriptor.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/signature/IdSignatureDescriptor.kt
@@ -30,23 +30,12 @@ open class IdSignatureDescriptor(override val mangler: KotlinMangler.DescriptorM
             d.accept(this, null)
         }
 
-        private fun createContainer() {
-            container = container?.let {
-                buildContainerSignature(it)
-            } ?: build()
-
-            reset(false)
-        }
-
         private fun reportUnexpectedDescriptor(descriptor: DeclarationDescriptor) {
             error("Unexpected descriptor $descriptor")
         }
 
-        private fun setDescription(descriptor: DeclarationDescriptor) {
-            if (container != null) {
-                description = DescriptorRenderer.SHORT_NAMES_IN_TYPES.render(descriptor)
-            }
-        }
+        override fun renderDeclarationForDescription(declaration: DeclarationDescriptor): String =
+            DescriptorRenderer.SHORT_NAMES_IN_TYPES.render(declaration)
 
         private fun collectParents(descriptor: DeclarationDescriptorNonRoot) {
             descriptor.containingDeclaration.accept(this, null)
@@ -76,7 +65,9 @@ open class IdSignatureDescriptor(override val mangler: KotlinMangler.DescriptorM
             collectParents(descriptor)
             setHashIdAndDescriptionFor(descriptor, isPropertyAccessor = false)
             isTopLevelPrivate = isTopLevelPrivate or descriptor.isTopLevelPrivate
-            setDescription(descriptor)
+
+            // If this is a local function, overwrite `description` with the descriptor's rendered form.
+            setDescriptionIfLocalDeclaration(descriptor)
             setExpected(descriptor.isExpect)
             platformSpecificFunction(descriptor)
         }
@@ -103,7 +94,7 @@ open class IdSignatureDescriptor(override val mangler: KotlinMangler.DescriptorM
                 }
             }
 
-            setDescription(descriptor)
+            setDescriptionIfLocalDeclaration(descriptor)
             setExpected(descriptor.isExpect)
             platformSpecificClass(descriptor)
         }
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/signature/IdSignatureSerializer.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/signature/IdSignatureSerializer.kt
index 344bae44c5c..17c7925a531 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/signature/IdSignatureSerializer.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/signature/IdSignatureSerializer.kt
@@ -73,14 +73,6 @@ class PublicIdSignatureComputer(val mangler: KotlinMangler.IrMangler) : IdSignat
             d.acceptVoid(this)
         }
 
-        private fun createContainer() {
-            container = container?.let {
-                buildContainerSignature(it)
-            } ?: build()
-
-            reset(false)
-        }
-
         private fun collectParents(declaration: IrDeclarationWithName) {
             declaration.parent.acceptVoid(this)
             if (declaration !is IrClass || !declaration.isFacadeClass) {
@@ -88,17 +80,13 @@ class PublicIdSignatureComputer(val mangler: KotlinMangler.IrMangler) : IdSignat
             }
         }
 
-        private fun setDescription(declaration: IrDeclaration) {
-            if (container != null) {
-                description = declaration.render()
-            }
-        }
+        override fun renderDeclarationForDescription(declaration: IrDeclaration): String = declaration.render()
 
         override fun visitElement(element: IrElement) =
             error("Unexpected element ${element.render()}")
 
         override fun visitErrorDeclaration(declaration: IrErrorDeclaration) {
-            description = declaration.render()
+            description = renderDeclarationForDescription(declaration)
         }
 
         override fun visitPackageFragment(declaration: IrPackageFragment) {
@@ -115,7 +103,7 @@ class PublicIdSignatureComputer(val mangler: KotlinMangler.IrMangler) : IdSignat
             if (declaration.kind == ClassKind.ENUM_ENTRY) {
                 classFqnSegments.add(MangleConstant.ENUM_ENTRY_CLASS_NAME)
             }
-            setDescription(declaration)
+            setDescriptionIfLocalDeclaration(declaration)
             setExpected(declaration.isExpect)
         }
 
@@ -132,7 +120,9 @@ class PublicIdSignatureComputer(val mangler: KotlinMangler.IrMangler) : IdSignat
                 collectParents(declaration)
                 isTopLevelPrivate = isTopLevelPrivate || declaration.isTopLevelPrivate
                 setHashIdAndDescriptionFor(declaration, isPropertyAccessor = false)
-                setDescription(declaration)
+
+                // If this is a local function, overwrite `description` with the IR function's rendered form.
+                setDescriptionIfLocalDeclaration(declaration)
             }
             setExpected(declaration.isExpect)
         }
@@ -178,7 +168,7 @@ class PublicIdSignatureComputer(val mangler: KotlinMangler.IrMangler) : IdSignat
             } else {
                 classFqnSegments.add(MangleConstant.TYPE_PARAMETER_MARKER_NAME)
             }
-            setHashIdAndDescription(declaration.index.toLong(), declaration.render(), isPropertyAccessor = false)
+            setHashIdAndDescription(declaration.index.toLong(), renderDeclarationForDescription(declaration), isPropertyAccessor = false)
         }
 
         override fun visitField(declaration: IrField) {
@@ -189,7 +179,7 @@ class PublicIdSignatureComputer(val mangler: KotlinMangler.IrMangler) : IdSignat
                 prop.acceptVoid(this)
                 createContainer()
                 classFqnSegments.add(MangleConstant.BACKING_FIELD_NAME)
-                description = declaration.render()
+                setDescriptionIfLocalDeclaration(declaration)
             } else {
                 collectParents(declaration)
                 setHashIdAndDescriptionFor(declaration, isPropertyAccessor = false)