diff --git a/src/logging/nm-logging.c b/src/logging/nm-logging.c
index 1e289d3719..d8353f2719 100644
--- a/src/logging/nm-logging.c
+++ b/src/logging/nm-logging.c
@@ -218,6 +218,12 @@ nm_logging_level_enabled (guint32 level)
 	return !!(log_level & level);
 }
 
+gboolean
+nm_logging_domain_enabled (guint32 domain)
+{
+	return !!(log_domains & domain);
+}
+
 void
 _nm_log (const char *loc,
          const char *func,
diff --git a/src/logging/nm-logging.h b/src/logging/nm-logging.h
index 44e49a712e..e3e05f59b2 100644
--- a/src/logging/nm-logging.h
+++ b/src/logging/nm-logging.h
@@ -95,6 +95,7 @@ void _nm_log (const char *loc,
 const char *nm_logging_level_to_string (void);
 char *nm_logging_domains_to_string (void);
 gboolean nm_logging_level_enabled (guint32 level);
+gboolean nm_logging_domain_enabled (guint32 domain);
 
 /* Undefine the nm-utils.h logging stuff to ensure errors */
 #undef nm_print_backtrace
diff --git a/src/ppp-manager/nm-ppp-manager.c b/src/ppp-manager/nm-ppp-manager.c
index 767b9315de..e863aabac6 100644
--- a/src/ppp-manager/nm-ppp-manager.c
+++ b/src/ppp-manager/nm-ppp-manager.c
@@ -798,7 +798,7 @@ create_pppd_cmd_line (NMPPPManager *self,
 	NMPPPManagerPrivate *priv = NM_PPP_MANAGER_GET_PRIVATE (self);
 	const char *ppp_binary;
 	NMCmdLine *cmd;
-	const char *ppp_debug;
+	gboolean ppp_debug;
 
 	g_return_val_if_fail (setting != NULL, NULL);
 
@@ -819,7 +819,11 @@ create_pppd_cmd_line (NMPPPManager *self,
 	/* NM handles setting the default route */
 	nm_cmd_line_add_string (cmd, "nodefaultroute");
 
-	ppp_debug = getenv ("NM_PPP_DEBUG");
+	ppp_debug = !!getenv ("NM_PPP_DEBUG");
+	if (   nm_logging_level_enabled (LOGL_DEBUG)
+	    && nm_logging_domain_enabled (LOGD_PPP))
+		ppp_debug = TRUE;
+
 	if (ppp_debug)
 		nm_cmd_line_add_string (cmd, "debug");