diff --git a/src/libsystemd/sd-bus/bus-internal.h b/src/libsystemd/sd-bus/bus-internal.h
index aaef6ac378..0e44897e0e 100644
--- a/src/libsystemd/sd-bus/bus-internal.h
+++ b/src/libsystemd/sd-bus/bus-internal.h
@@ -362,7 +362,7 @@ bool path_complex_pattern(const char *pattern, const char *value) _pure_;
 bool namespace_simple_pattern(const char *pattern, const char *value) _pure_;
 bool path_simple_pattern(const char *pattern, const char *value) _pure_;
 
-int bus_message_type_from_string(const char *s, uint8_t *u) _pure_;
+int bus_message_type_from_string(const char *s, uint8_t *u);
 const char *bus_message_type_to_string(uint8_t u) _pure_;
 
 #define error_name_is_valid interface_name_is_valid