diff --git a/lasso/debug.h b/lasso/debug.h
index ce294ac7..f98f7882 100644
--- a/lasso/debug.h
+++ b/lasso/debug.h
@@ -37,6 +37,7 @@ LASSO_EXPORT extern gboolean lasso_flag_memory_debug;
 LASSO_EXPORT extern gboolean lasso_flag_strict_checking;
 LASSO_EXPORT extern gboolean lasso_flag_add_signature;
 LASSO_EXPORT extern gboolean lasso_flag_sign_messages;
+LASSO_EXPORT extern gboolean lasso_flag_thin_sessions;
 
 #ifdef __cplusplus
 }
diff --git a/lasso/id-ff/session.c b/lasso/id-ff/session.c
index 6aad9160..d5294ff3 100644
--- a/lasso/id-ff/session.c
+++ b/lasso/id-ff/session.c
@@ -195,6 +195,9 @@ lasso_session_add_assertion_simple(LassoSession *session, const char *providerID
 	g_return_val_if_fail(providerID != NULL, LASSO_PARAM_ERROR_INVALID_VALUE);
 	g_return_val_if_fail(assertion != NULL, LASSO_PARAM_ERROR_INVALID_VALUE);
 
+	if (lasso_flag_thin_sessions) { /* do not store the full assertion */
+		return 0;
+	}
 	g_hash_table_insert(session->assertions, g_strdup(providerID),
 			g_object_ref(assertion));
 
diff --git a/lasso/lasso.c b/lasso/lasso.c
index 98248dac..3d127f9b 100644
--- a/lasso/lasso.c
+++ b/lasso/lasso.c
@@ -95,6 +95,8 @@ gboolean lasso_flag_add_signature = TRUE;
 static void lasso_flag_parse_environment_variable();
 /* do not sign messages */
 gboolean lasso_flag_sign_messages = TRUE;
+/* thin sessions */
+gboolean lasso_flag_thin_sessions = FALSE;
 
 #ifndef LASSO_FLAG_ENV_VAR
 #define LASSO_FLAG_ENV_VAR "LASSO_FLAG"
@@ -317,6 +319,9 @@ void lasso_set_flag(char *flag) {
 			lasso_flag_sign_messages = value;
 			continue;
 		}
+		if (lasso_strisequal(flag,"thin-sessions")) {
+			lasso_flag_thin_sessions = value;
+		}
 	} while (FALSE);
 }