diff --git a/gcore/gdaldrivermanager.cpp b/gcore/gdaldrivermanager.cpp
index e05efde1dfe5..3c65da216ff1 100644
--- a/gcore/gdaldrivermanager.cpp
+++ b/gcore/gdaldrivermanager.cpp
@@ -1287,6 +1287,7 @@ static const char *const apszProxyMetadataItems[] = {
     GDAL_DCAP_NONSPATIAL,
     GDAL_DMD_CONNECTION_PREFIX,
     GDAL_DCAP_VECTOR_TRANSLATE_FROM,
+    GDAL_DMD_PLUGIN_INSTALLATION_MESSAGE,
 };
 
 const char *GDALPluginDriverProxy::GetMetadataItem(const char *pszName,
@@ -1331,8 +1332,7 @@ const char *GDALPluginDriverProxy::GetMetadataItem(const char *pszName,
             }
             return pszValue;
         }
-        else if (!EQUAL(pszName, GDAL_DMD_PLUGIN_INSTALLATION_MESSAGE) &&
-                 m_oSetMetadataItems.find(pszName) != m_oSetMetadataItems.end())
+        else if (m_oSetMetadataItems.find(pszName) != m_oSetMetadataItems.end())
         {
             return GDALDriver::GetMetadataItem(pszName, pszDomain);
         }