diff --git a/src/os/win32/win32_sigar.c b/src/os/win32/win32_sigar.c
index 800e9938..1200ad6f 100644
--- a/src/os/win32/win32_sigar.c
+++ b/src/os/win32/win32_sigar.c
@@ -327,6 +327,10 @@ int sigar_os_close(sigar_t *sigar)
 
     retval = RegCloseKey(sigar->handle);
 
+    if (sigar->adv_handle) {
+        FreeLibrary(sigar->adv_handle);
+    }
+
     if (sigar->ip_handle) {
         FreeLibrary(sigar->ip_handle);
     }