diff --git a/src/org.gnome.Sysprof2.xml b/src/org.gnome.Sysprof2.xml
index 442d32df..ede0326f 100644
--- a/src/org.gnome.Sysprof2.xml
+++ b/src/org.gnome.Sysprof2.xml
@@ -14,13 +14,12 @@
     the resulting fd back to the calling process.
   -->
   <method name="PerfEventOpen">
+   <annotation name="org.gtk.GDBus.C.UnixFD" value="true"/>
    <arg name="options" type="a{sv}" direction="in"/>
    <arg name="pid" type="i" direction="in"/>
    <arg name="cpu" type="i" direction="in"/>
    <arg name="flags" type="t" direction="in"/>
-   <arg name="perf_stream_fd" type="h" direction="out">
-     <annotation name="org.gtk.GDBus.C.UnixFD" value="true"/>
-   </arg>
+   <arg name="perf_stream_fd" type="h" direction="out"/>
   </method>
 
   <!--
diff --git a/src/org.gnome.Sysprof3.Profiler.xml b/src/org.gnome.Sysprof3.Profiler.xml
index fe88a106..3d230948 100644
--- a/src/org.gnome.Sysprof3.Profiler.xml
+++ b/src/org.gnome.Sysprof3.Profiler.xml
@@ -29,10 +29,9 @@
       The contents of @options are implementation specific.
     -->
     <method name="Start">
+      <annotation name="org.gtk.GDBus.C.UnixFD" value="true"/>
       <arg type="a{sv}" name="options" direction="in"/>
-      <arg type="h" name="fd" direction="in">
-        <annotation name="org.gtk.GDBus.C.UnixFD" value="true"/>
-      </arg>
+      <arg type="h" name="fd" direction="in"/>
     </method>
     <!--
       Stop:
diff --git a/src/org.gnome.Sysprof3.Service.xml b/src/org.gnome.Sysprof3.Service.xml
index f9808afd..de325a99 100644
--- a/src/org.gnome.Sysprof3.Service.xml
+++ b/src/org.gnome.Sysprof3.Service.xml
@@ -15,16 +15,13 @@
       the resulting fd back to the calling process.
     -->
     <method name="PerfEventOpen">
+      <annotation name="org.gtk.GDBus.C.UnixFD" value="true"/>
       <arg name="options" type="a{sv}" direction="in"/>
       <arg name="pid" type="i" direction="in"/>
       <arg name="cpu" type="i" direction="in"/>
-      <arg name="group_fd" type="h" direction="in">
-        <annotation name="org.gtk.GDBus.C.UnixFD" value="true"/>
-      </arg>
+      <arg name="group_fd" type="h" direction="in"/>
       <arg name="flags" type="t" direction="in"/>
-      <arg name="perf_stream_fd" type="h" direction="out">
-        <annotation name="org.gtk.GDBus.C.UnixFD" value="true"/>
-      </arg>
+      <arg name="perf_stream_fd" type="h" direction="out"/>
     </method>
 
     <!--
@@ -58,10 +55,9 @@
       Since: 3.34
     -->
     <method name="GetProcFd">
+      <annotation name="org.gtk.GDBus.C.UnixFD" value="true"/>
       <arg name="path" type="ay" direction="in"/>
-      <arg name="fd" type="h" direction="out">
-        <annotation name="org.gtk.GDBus.C.UnixFD" value="true"/>
-      </arg>
+      <arg name="fd" type="h" direction="out"/>
     </method>
 
     <!--