diff --git a/src/pulsecore/protocol-dbus.c b/src/pulsecore/protocol-dbus.c
index 03cebc1ea..adc1f38d3 100644
--- a/src/pulsecore/protocol-dbus.c
+++ b/src/pulsecore/protocol-dbus.c
@@ -360,7 +360,7 @@ static enum find_result_t find_handler_by_method(struct call_info *call_info) {
 
     PA_HASHMAP_FOREACH(call_info->iface_entry, call_info->obj_entry->interfaces, state) {
         if ((call_info->method_handler = pa_hashmap_get(call_info->iface_entry->method_handlers, call_info->method))) {
-            call_info->expected_method_sig = pa_hashmap_get(call_info->iface_entry->method_signatures, call_info->method);
+            pa_assert_se(call_info->expected_method_sig = pa_hashmap_get(call_info->iface_entry->method_signatures, call_info->method));
 
             if (pa_streq(call_info->method_sig, call_info->expected_method_sig))
                 return FOUND_METHOD;
@@ -469,7 +469,7 @@ static enum find_result_t find_handler(struct call_info *call_info) {
             return NO_SUCH_INTERFACE;
 
         else if ((call_info->method_handler = pa_hashmap_get(call_info->iface_entry->method_handlers, call_info->method))) {
-            call_info->expected_method_sig = pa_hashmap_get(call_info->iface_entry->method_signatures, call_info->method);
+            pa_assert_se(call_info->expected_method_sig = pa_hashmap_get(call_info->iface_entry->method_signatures, call_info->method));
 
             if (!pa_streq(call_info->method_sig, call_info->expected_method_sig))
                 return INVALID_METHOD_SIG;