diff --git a/compiler/testData/codegen/box/cinterop/auxiliarySources.kt b/compiler/testData/codegen/box/cinterop/auxiliarySources.kt
index 21dc6922ba3..447a97bc84d 100644
--- a/compiler/testData/codegen/box/cinterop/auxiliarySources.kt
+++ b/compiler/testData/codegen/box/cinterop/auxiliarySources.kt
@@ -9,11 +9,11 @@
 // FILE: auxiliaryCppSources.h
 #ifdef __cplusplus
 extern "C" {
-    #endif
+#endif
 
-    const char* name();
+const char* name();
 
-    #ifdef __cplusplus
+#ifdef __cplusplus
 }
 #endif
 
@@ -23,7 +23,7 @@ extern "C" {
 
 static std::string _name = "OK";
 
-const char* name() {
+extern "C" const char* name() {
     return _name.c_str();
 }
 
diff --git a/compiler/testData/codegen/box/cinterop/incompleteTypes.kt b/compiler/testData/codegen/box/cinterop/incompleteTypes.kt
index 52f980911dd..245b67aa337 100644
--- a/compiler/testData/codegen/box/cinterop/incompleteTypes.kt
+++ b/compiler/testData/codegen/box/cinterop/incompleteTypes.kt
@@ -9,29 +9,29 @@
 // FILE: incompleteTypes.h
 #ifdef __cplusplus
 extern "C" {
-    #endif
+#endif
 
 // Forward declaration.
-    struct S;
-    extern struct S s;
+struct S;
+extern struct S s;
 
-    const char* getContent(struct S* s);
-    void setContent(struct S* s, const char* name);
+const char* getContent(struct S* s);
+void setContent(struct S* s, const char* name);
 
-    union U;
-    extern union U u;
+union U;
+extern union U u;
 
-    double getDouble(union U* u);
-    void setDouble(union U* u, double value);
+double getDouble(union U* u);
+void setDouble(union U* u, double value);
 
 // Global array of unknown size.
-    extern char array[];
+extern char array[];
 
 
-    int arrayLength();
-    void setArrayValue(char* array, char value);
+int arrayLength();
+void setArrayValue(char* array, char value);
 
-    #ifdef __cplusplus
+#ifdef __cplusplus
 }
 #endif
 
@@ -41,52 +41,52 @@ extern "C" {
 
 extern "C" {
 
-    struct S {
-        std::string name;
-    };
+struct S {
+    std::string name;
+};
 
-    S s = {
-        .name = "initial"
-    };
+S s = {
+    .name = "initial"
+};
 
-    void setContent(struct S* s, const char* name) {
-        // Note that copy here is intentional: we use it as a workaround
-        // for short lifetime of copy of the passed Kotlin string.
-            s->name = name;
-    }
+void setContent(struct S* s, const char* name) {
+    // Note that copy here is intentional: we use it as a workaround
+    // for short lifetime of copy of the passed Kotlin string.
+        s->name = name;
+}
 
-    const char* getContent(struct S* s) {
-        return s->name.c_str();
-    }
+const char* getContent(struct S* s) {
+    return s->name.c_str();
+}
 
-    union U {
-        float f;
-        double d;
-    };
+union U {
+    float f;
+    double d;
+};
 
-    void setDouble(union U* u, double value) {
-            u->d = value;
-    }
+void setDouble(union U* u, double value) {
+        u->d = value;
+}
 
-    double getDouble(union U* u) {
-        return u->d;
-    }
+double getDouble(union U* u) {
+    return u->d;
+}
 
-    union U u = {
-        .d = 0.0
-    };
+union U u = {
+    .d = 0.0
+};
 
-    char array[5] = { 0, 0, 0, 0, 0 };
+char array[5] = { 0, 0, 0, 0, 0 };
 
-    void setArrayValue(char* array, char value) {
-        for (int i = 0; i < 5; ++i) {
-        array[i] = value;
-    }
-    }
+void setArrayValue(char* array, char value) {
+    for (int i = 0; i < 5; ++i) {
+    array[i] = value;
+}
+}
 
-    int arrayLength() {
-        return sizeof(array) / sizeof(char);
-    }
+int arrayLength() {
+    return sizeof(array) / sizeof(char);
+}
 
 }
 
diff --git a/compiler/testData/codegen/box/cinterop/leakMemoryWithRunningThreadUnchecked.kt b/compiler/testData/codegen/box/cinterop/leakMemoryWithRunningThreadUnchecked.kt
index 1d24e97e6ea..ae507a31558 100644
--- a/compiler/testData/codegen/box/cinterop/leakMemoryWithRunningThreadUnchecked.kt
+++ b/compiler/testData/codegen/box/cinterop/leakMemoryWithRunningThreadUnchecked.kt
@@ -7,11 +7,11 @@ void test_RunInNewThread(void (*)());
 // FILE: leakMemoryWithRunningThreadUnchecked.h
 #ifdef __cplusplus
 extern "C" {
-    #endif
+#endif
 
-    void test_RunInNewThread(void (*)());
+void test_RunInNewThread(void (*)());
 
-    #ifdef __cplusplus
+#ifdef __cplusplus
 }
 #endif