diff --git a/kotlin-analysis-api/src/main/kotlin/com/google/devtools/ksp/impl/symbol/kotlin/KSClassDeclarationImpl.kt b/kotlin-analysis-api/src/main/kotlin/com/google/devtools/ksp/impl/symbol/kotlin/KSClassDeclarationImpl.kt
index e5161bb546..06fef7653d 100644
--- a/kotlin-analysis-api/src/main/kotlin/com/google/devtools/ksp/impl/symbol/kotlin/KSClassDeclarationImpl.kt
+++ b/kotlin-analysis-api/src/main/kotlin/com/google/devtools/ksp/impl/symbol/kotlin/KSClassDeclarationImpl.kt
@@ -211,6 +211,9 @@ internal fun KtClassOrObjectSymbol.toModifiers(): Set<Modifier> {
         if (visibility != JavaVisibilities.PackageVisibility) {
             result.add(visibility.toModifier())
         }
+        if (isFun) {
+            result.add(Modifier.FUN)
+        }
         if (isInline) {
             result.add(Modifier.INLINE)
         }
diff --git a/test-utils/src/main/kotlin/com/google/devtools/ksp/processor/JavaModifierProcessor.kt b/test-utils/src/main/kotlin/com/google/devtools/ksp/processor/JavaModifierProcessor.kt
index 8ac070fe5e..97442d7641 100644
--- a/test-utils/src/main/kotlin/com/google/devtools/ksp/processor/JavaModifierProcessor.kt
+++ b/test-utils/src/main/kotlin/com/google/devtools/ksp/processor/JavaModifierProcessor.kt
@@ -34,7 +34,7 @@ class JavaModifierProcessor : AbstractTestProcessor() {
     override fun process(resolver: Resolver): List<KSAnnotated> {
         listOf("ALib", "ASrc").forEach { clsName ->
             resolver.getClassDeclarationByName(clsName)!!.let { cls ->
-                println(cls.modifiers.contains(Modifier.FUN))
+                assert(cls.modifiers.contains(Modifier.FUN))
             }
         }
 
diff --git a/test-utils/testData/api/javaModifiers.kt b/test-utils/testData/api/javaModifiers.kt
index 7254b7629f..cd458f23dc 100644
--- a/test-utils/testData/api/javaModifiers.kt
+++ b/test-utils/testData/api/javaModifiers.kt
@@ -102,6 +102,10 @@
 // OuterKotlinClass: OPEN : PUBLIC
 // END
 // MODULE: module1
+// FILE: ALib.kt
+fun interface ALib {
+    fun test(): Boolean
+}
 // FILE: DependencyOuterJavaClass.java
 public class DependencyOuterJavaClass {
     public class DependencyInnerJavaClass {}
@@ -152,6 +156,10 @@ open class DependencyOuterKotlinClass {
     fun synchronizedFun(): String = ""
 }
 // MODULE: main(module1)
+// FILE: ASrc.kt
+fun interface ASrc {
+    fun test(): Boolean
+}
 // FILE: a.kt
 annotation class Test