diff --git a/tools/versioner/tests/missing_api/expected_fail b/tools/versioner/tests/missing_api/expected_fail
index 18e7845..9f097f7 100644
--- a/tools/versioner/tests/missing_api/expected_fail
+++ b/tools/versioner/tests/missing_api/expected_fail
@@ -1,4 +1,4 @@
   foo: introduced = 9
-    extern declaration @ headers/foo.h:1:1
+    extern declaration @ headers/foo.h:5:1
       introduced = 9
 versioner: version check failed
diff --git a/tools/versioner/tests/missing_api/headers/foo.h b/tools/versioner/tests/missing_api/headers/foo.h
index 3ff3ff7..c201dbb 100644
--- a/tools/versioner/tests/missing_api/headers/foo.h
+++ b/tools/versioner/tests/missing_api/headers/foo.h
@@ -1 +1,9 @@
-int foo() __INTRODUCED_IN(9);
\ No newline at end of file
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+int foo() __INTRODUCED_IN(9);
+
+#if defined(__cplusplus)
+}
+#endif