diff --git a/a_sync/a_sync/_flags.pxd b/a_sync/a_sync/_flags.pxd
index 6dd06222..1d216505 100644
--- a/a_sync/a_sync/_flags.pxd
+++ b/a_sync/a_sync/_flags.pxd
@@ -1,3 +1,3 @@
 cdef inline bint negate_if_necessary(str flag, bint flag_value)
-cdef inline bint validate_flag_value(str flag, object flag_value)
+cdef bint validate_flag_value(str flag, object flag_value)
 cdef bint validate_and_negate_if_necessary(str flag, object flag_value)
diff --git a/a_sync/a_sync/base.pyx b/a_sync/a_sync/base.pyx
index 139fc216..dfd4285f 100644
--- a/a_sync/a_sync/base.pyx
+++ b/a_sync/a_sync/base.pyx
@@ -202,7 +202,7 @@ cdef str _parse_flag_name_from_list(object cls, object items):
     return present_flags[0]
 
 
-cdef bint _get_a_sync_flag_value_from_class_def(object cls, str flag):
+cdef inline bint _get_a_sync_flag_value_from_class_def(object cls, str flag):
     cdef object spec
     for spec in [cls, *cls.__bases__]:
         if flag in spec.__dict__: