diff -Naur a/gobject/gparamspecs.c b/gobject/gparamspecs.c
--- a/gobject/gparamspecs.c	2022-09-17 20:38:17.000000000 +0200
+++ b/gobject/gparamspecs.c	2022-10-08 16:50:51.134175611 +0200
@@ -894,6 +894,9 @@
 {
   GParamSpec *param = value->data[0].v_pointer;
 
+  if (param == NULL)
+    return FALSE;
+
   return g_value_type_compatible (G_PARAM_SPEC_TYPE (param), G_PARAM_SPEC_VALUE_TYPE (pspec));
 }