diff --git a/compiler/frontend.common/src/org/jetbrains/kotlin/diagnostics/KtDiagnosticReportHelpers.kt b/compiler/frontend.common/src/org/jetbrains/kotlin/diagnostics/KtDiagnosticReportHelpers.kt
index f80a30b1e3f..610fbfdbb9b 100644
--- a/compiler/frontend.common/src/org/jetbrains/kotlin/diagnostics/KtDiagnosticReportHelpers.kt
+++ b/compiler/frontend.common/src/org/jetbrains/kotlin/diagnostics/KtDiagnosticReportHelpers.kt
@@ -15,7 +15,7 @@ fun DiagnosticReporter.reportOn(
     context: DiagnosticContext,
     positioningStrategy: AbstractSourceElementPositioningStrategy? = null
 ) {
-    source?.let { report(factory.on(it, positioningStrategy), context) }
+    report(factory.on(requireSourceNotNull(source), positioningStrategy), context)
 }
 
 fun <A : Any> DiagnosticReporter.reportOn(
@@ -25,7 +25,7 @@ fun <A : Any> DiagnosticReporter.reportOn(
     context: DiagnosticContext,
     positioningStrategy: AbstractSourceElementPositioningStrategy? = null
 ) {
-    source?.let { report(factory.on(it, a, positioningStrategy), context) }
+    report(factory.on(requireSourceNotNull(source), a, positioningStrategy), context)
 }
 
 fun <A : Any, B : Any> DiagnosticReporter.reportOn(
@@ -36,7 +36,7 @@ fun <A : Any, B : Any> DiagnosticReporter.reportOn(
     context: DiagnosticContext,
     positioningStrategy: AbstractSourceElementPositioningStrategy? = null
 ) {
-    source?.let { report(factory.on(it, a, b, positioningStrategy), context) }
+    report(factory.on(requireSourceNotNull(source), a, b, positioningStrategy), context)
 }
 
 fun <A : Any, B : Any, C : Any> DiagnosticReporter.reportOn(
@@ -48,7 +48,7 @@ fun <A : Any, B : Any, C : Any> DiagnosticReporter.reportOn(
     context: DiagnosticContext,
     positioningStrategy: AbstractSourceElementPositioningStrategy? = null
 ) {
-    source?.let { report(factory.on(it, a, b, c, positioningStrategy), context) }
+    report(factory.on(requireSourceNotNull(source), a, b, c, positioningStrategy), context)
 }
 
 fun <A : Any, B : Any, C : Any, D : Any> DiagnosticReporter.reportOn(
@@ -61,9 +61,12 @@ fun <A : Any, B : Any, C : Any, D : Any> DiagnosticReporter.reportOn(
     context: DiagnosticContext,
     positioningStrategy: AbstractSourceElementPositioningStrategy? = null
 ) {
-    source?.let { report(factory.on(it, a, b, c, d, positioningStrategy), context) }
+    report(factory.on(requireSourceNotNull(source), a, b, c, d, positioningStrategy), context)
 }
 
+private fun requireSourceNotNull(source: AbstractKtSourceElement?): AbstractKtSourceElement =
+    requireNotNull(source) { "source must not be null" }
+
 fun DiagnosticReporter.reportOn(
     source: AbstractKtSourceElement?,
     factory: KtDiagnosticFactoryForDeprecation0,
@@ -125,4 +128,4 @@ fun <F : AbstractKtDiagnosticFactory> KtDiagnosticFactoryForDeprecation<F>.choos
     } else {
         warningFactory
     }
-}
\ No newline at end of file
+}