diff --git a/cfg/gtk.cfg b/cfg/gtk.cfg
index 53e545dd9..42d916549 100644
--- a/cfg/gtk.cfg
+++ b/cfg/gtk.cfg
@@ -2179,9 +2179,13 @@
     <leak-ignore/>
     <noreturn>false</noreturn>
   </function>
+  <!-- void g_clear_error (GError **err); -->
   <function name="g_clear_error">
-    <leak-ignore/>
     <noreturn>false</noreturn>
+    <returnValue type="void"/>
+    <arg nr="1">
+      <not-bool/>
+    </arg>
   </function>
   <function name="g_clear_pointer">
     <leak-ignore/>
@@ -3059,9 +3063,17 @@
     <leak-ignore/>
     <noreturn>false</noreturn>
   </function>
+  <!-- void g_prefix_error (GError **err, const gchar *format, ...); -->
   <function name="g_prefix_error">
     <leak-ignore/>
     <noreturn>false</noreturn>
+    <returnValue type="void"/>
+    <arg nr="1" direction="inout"/>
+    <formatstr/>
+    <arg nr="2" direction="in">
+      <not-uninit/>
+      <formatstr/>
+    </arg>
   </function>
   <!-- void g_print (const gchar *format, ...); -->
   <!-- void g_printerr (const gchar *format, ...); -->
@@ -3092,13 +3104,30 @@
     <leak-ignore/>
     <noreturn>false</noreturn>
   </function>
+  <!-- void g_propagate_error (GError **dest, GError *src); -->
   <function name="g_propagate_error">
-    <leak-ignore/>
     <noreturn>false</noreturn>
+    <returnValue type="void"/>
+    <arg nr="1" direction="out"/>
+    <arg nr="2">
+      <not-null/>
+    </arg>
   </function>
+  <!-- void g_propagate_prefixed_error (GError **dest,
+                                        GError *src,
+                                        const gchar *format,
+                                        ...); -->
   <function name="g_propagate_prefixed_error">
-    <leak-ignore/>
     <noreturn>false</noreturn>
+    <returnValue type="void"/>
+    <arg nr="1" direction="out"/>
+    <arg nr="2">
+      <not-uninit/>
+    </arg>
+    <formatstr/>
+    <arg nr="3" direction="in">
+      <formatstr/>
+    </arg>
   </function>
   <function name="g_ptr_array_remove">
     <leak-ignore/>