diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrConverter.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrConverter.kt
index 92536f30fe4..0f97a3fbe3c 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrConverter.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrConverter.kt
@@ -509,7 +509,7 @@ class Fir2IrConverter(
             }
             is FirScript -> {
                 require(parent is IrFile)
-                val irScript = declarationStorage.getOrCreateIrScript(declaration)
+                val irScript = declarationStorage.createIrScript(declaration)
                 addDeclarationToParentIfNeeded(irScript)
                 declarationStorage.withScope(irScript.symbol) {
                     irScript.parent = parent
diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrDeclarationStorage.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrDeclarationStorage.kt
index 3d644cabbc7..517fb02de4e 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrDeclarationStorage.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrDeclarationStorage.kt
@@ -1158,8 +1158,8 @@ class Fir2IrDeclarationStorage(
         return scriptCache[script]
     }
 
-    fun getOrCreateIrScript(script: FirScript): IrScript {
-        getCachedIrScript(script)?.let { return it }
+    fun createIrScript(script: FirScript): IrScript {
+        getCachedIrScript(script)?.let { error("IrScript already created: ${script.render()}") }
         val symbol = createScriptSymbol(signatureComposer.composeSignature(script))
         return callablesGenerator.createIrScript(script, symbol).also {
             scriptCache[script] = it