diff --git a/src/util/disk_cache_os.h b/src/util/disk_cache_os.h
index 9fbd4bbbffc..7be6a26e689 100644
--- a/src/util/disk_cache_os.h
+++ b/src/util/disk_cache_os.h
@@ -34,6 +34,10 @@
 
 #include "util/fossilize_db.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Number of bits to mask off from a cache key to get an index. */
 #define CACHE_INDEX_KEY_BITS 16
 
@@ -141,6 +145,10 @@ disk_cache_mmap_cache_index(void *mem_ctx, struct disk_cache *cache,
 void
 disk_cache_destroy_mmap(struct disk_cache *cache);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif
 
 #endif /* DISK_CACHE_OS_H */