diff --git a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ModuleGenerator.kt b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ModuleGenerator.kt
index e2c39f64687..0c5eef87824 100644
--- a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ModuleGenerator.kt
+++ b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ModuleGenerator.kt
@@ -52,7 +52,7 @@ open class ModuleGenerator(
         ExternalDependenciesGenerator(context.symbolTable, irProviders).generateUnboundSymbolsAsDependencies()
     }
 
-    private fun generateSingleFile(irDeclarationGenerator: DeclarationGenerator, ktFile: KtFile, module: IrModuleFragment): IrFileImpl {
+    fun generateSingleFile(irDeclarationGenerator: DeclarationGenerator, ktFile: KtFile, module: IrModuleFragment): IrFileImpl {
         val irFile = createEmptyIrFile(ktFile, module)
 
         val constantValueGenerator = irDeclarationGenerator.context.constantValueGenerator
@@ -85,7 +85,7 @@ open class ModuleGenerator(
         return irFile
     }
 
-    private fun createEmptyIrFile(ktFile: KtFile, module: IrModuleFragment): IrFileImpl {
+     fun createEmptyIrFile(ktFile: KtFile, module: IrModuleFragment): IrFileImpl {
         val fileEntry = PsiIrFileEntry(ktFile)
         val packageFragmentDescriptor = context.moduleDescriptor.findPackageFragmentForFile(ktFile)!!
         return IrFileImpl(fileEntry, packageFragmentDescriptor, module).apply {
diff --git a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/fragments/FragmentModuleGenerator.kt b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/fragments/FragmentModuleGenerator.kt
index dd0ccd67287..08c6a80b32e 100644
--- a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/fragments/FragmentModuleGenerator.kt
+++ b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/fragments/FragmentModuleGenerator.kt
@@ -12,8 +12,7 @@ import org.jetbrains.kotlin.ir.declarations.impl.IrModuleFragmentImpl
 import org.jetbrains.kotlin.ir.util.patchDeclarationParents
 import org.jetbrains.kotlin.psi.KtBlockCodeFragment
 import org.jetbrains.kotlin.psi.KtFile
-import org.jetbrains.kotlin.psi2ir.generators.GeneratorContext
-import org.jetbrains.kotlin.psi2ir.generators.ModuleGenerator
+import org.jetbrains.kotlin.psi2ir.generators.*
 import org.jetbrains.kotlin.resolve.lazy.descriptors.findPackageFragmentForFile
 
 class FragmentModuleGenerator(
@@ -24,18 +23,26 @@ class FragmentModuleGenerator(
     override fun generateModuleFragment(
         ktFiles: Collection<KtFile>,
     ): IrModuleFragment {
-        val ktBlockCodeFragment = ktFiles.singleOrNull() as? KtBlockCodeFragment
-            ?: TODO("Multiple fragments in one compilation not understood and implemented yet")
+        assert(ktFiles.singleOrNull { it is KtBlockCodeFragment} != null) {
+            "Amongst all files passed to the FragmentModuleGenerator should be exactly one KtBlockCodeFragment"
+        }
         return IrModuleFragmentImpl(context.moduleDescriptor, context.irBuiltIns).also { irModule ->
             val irDeclarationGenerator = FragmentDeclarationGenerator(context, fragmentInfo)
-            irModule.files.add(
-                createEmptyIrFile(ktBlockCodeFragment).apply {
-                    declarations.add(
-                        irDeclarationGenerator.generateClassForCodeFragment(ktBlockCodeFragment)
-                    )
-                    patchDeclarationParents()
-                }
-            )
+            ktFiles.forEach { ktFile ->
+                irModule.files.add(
+                    if (ktFile is KtBlockCodeFragment) {
+                        createEmptyIrFile(ktFile).apply {
+                            declarations.add(
+                                irDeclarationGenerator.generateClassForCodeFragment(ktFile)
+                            )
+                            patchDeclarationParents()
+                        }
+                    } else {
+                        val fileContext = context.createFileScopeContext(ktFile)
+                        generateSingleFile(DeclarationGenerator(fileContext), ktFile, irModule)
+                    }
+                )
+            }
         }
     }