diff --git a/install.cpp b/install.cpp
index 8d36cb5..4d73aa9 100644
--- a/install.cpp
+++ b/install.cpp
@@ -46,7 +46,7 @@
 static const float DEFAULT_IMAGE_PROGRESS_FRACTION = 0.1;
 
 // If the package contains an update binary, extract it and run it.
-extern "C" int
+static int
 try_update_binary(const char *path, ZipArchive *zip, int* wipe_cache) {
     const ZipEntry* binary_entry =
             mzFindZipEntry(zip, ASSUMED_UPDATE_BINARY_NAME);