diff --git a/src/libstrongswan/plugins/pem/pem_plugin.c b/src/libstrongswan/plugins/pem/pem_plugin.c
index d102e1535..e67cde53e 100644
--- a/src/libstrongswan/plugins/pem/pem_plugin.c
+++ b/src/libstrongswan/plugins/pem/pem_plugin.c
@@ -78,7 +78,8 @@ METHOD(plugin_t, get_features, int,
 		/* certificate PEM decoding */
 		PLUGIN_REGISTER(CERT_DECODE, pem_certificate_load, FALSE),
 			PLUGIN_PROVIDE(CERT_DECODE, CERT_ANY),
-				PLUGIN_DEPENDS(CERT_DECODE, CERT_ANY),
+				PLUGIN_SDEPEND(CERT_DECODE, CERT_X509),
+				PLUGIN_SDEPEND(CERT_DECODE, CERT_GPG),
 		PLUGIN_REGISTER(CERT_DECODE, pem_certificate_load, FALSE),
 			PLUGIN_PROVIDE(CERT_DECODE, CERT_X509),
 				PLUGIN_DEPENDS(CERT_DECODE, CERT_X509),