diff --git a/components/geckoport/Components/GeckoBrowser.pas b/components/geckoport/Components/GeckoBrowser.pas
index eedc36e26..59a3e83c7 100755
--- a/components/geckoport/Components/GeckoBrowser.pas
+++ b/components/geckoport/Components/GeckoBrowser.pas
@@ -42,6 +42,10 @@ unit GeckoBrowser;
   {$DEFINE extdecl:=cdecl}
 {$ENDIF}
 
+{$IFNDEF FPC_HAS_CONSTREF}
+  {$DEFINE constref:=const}
+{$ENDIF}
+
 {$IFDEF LCLCocoa}
   {$MODESWITCH ObjectiveC1}
 {$ENDIF}
diff --git a/components/geckoport/Components/GeckoChromeWindow.pas b/components/geckoport/Components/GeckoChromeWindow.pas
index ec7fd6970..2df9a57c4 100755
--- a/components/geckoport/Components/GeckoChromeWindow.pas
+++ b/components/geckoport/Components/GeckoChromeWindow.pas
@@ -42,6 +42,10 @@ unit GeckoChromeWindow;
   {$DEFINE extdecl:=cdecl}
 {$ENDIF}
 
+{$IFNDEF FPC_HAS_CONSTREF}
+  {$DEFINE constref:=const}
+{$ENDIF}
+
 {$IFDEF LCLCocoa}
   {$MODESWITCH ObjectiveC1}
 {$ENDIF}
diff --git a/components/geckoport/each-version/nsXPCOM_safe17.pas b/components/geckoport/each-version/nsXPCOM_safe17.pas
index 6cee4c1a3..0fd7221c1 100644
--- a/components/geckoport/each-version/nsXPCOM_safe17.pas
+++ b/components/geckoport/each-version/nsXPCOM_safe17.pas
@@ -8,6 +8,10 @@ unit nsXPCOM_safe17;
   {$DEFINE extdecl:=cdecl}
 {$ENDIF}
 
+{$IFNDEF FPC_HAS_CONSTREF}
+  {$DEFINE constref:=const}
+{$ENDIF}
+
 interface
 
 uses
diff --git a/components/geckoport/each-version/nsXPCOM_safe18.pas b/components/geckoport/each-version/nsXPCOM_safe18.pas
index 6388ab3cb..051db5e57 100644
--- a/components/geckoport/each-version/nsXPCOM_safe18.pas
+++ b/components/geckoport/each-version/nsXPCOM_safe18.pas
@@ -8,6 +8,10 @@ unit nsXPCOM_safe18;
   {$DEFINE extdecl:=cdecl}
 {$ENDIF}
 
+{$IFNDEF FPC_HAS_CONSTREF}
+  {$DEFINE constref:=const}
+{$ENDIF}
+
 interface
 
 uses
diff --git a/components/geckoport/each-version/nsXPCOM_safe19.pas b/components/geckoport/each-version/nsXPCOM_safe19.pas
index a9c94e999..6ea68584c 100644
--- a/components/geckoport/each-version/nsXPCOM_safe19.pas
+++ b/components/geckoport/each-version/nsXPCOM_safe19.pas
@@ -8,6 +8,10 @@ unit nsXPCOM_safe19;
   {$DEFINE extdecl:=cdecl}
 {$ENDIF}
 
+{$IFNDEF FPC_HAS_CONSTREF}
+  {$DEFINE constref:=const}
+{$ENDIF}
+
 interface
 
 uses
diff --git a/components/geckoport/each-version/nsXPCOM_std17.pas b/components/geckoport/each-version/nsXPCOM_std17.pas
index e816ff928..392416bf9 100644
--- a/components/geckoport/each-version/nsXPCOM_std17.pas
+++ b/components/geckoport/each-version/nsXPCOM_std17.pas
@@ -8,6 +8,10 @@ unit nsXPCOM_std17;
   {$DEFINE extdecl:=cdecl}
 {$ENDIF}
 
+{$IFNDEF FPC_HAS_CONSTREF}
+  {$DEFINE constref:=const}
+{$ENDIF}
+
 interface
 
 uses
diff --git a/components/geckoport/each-version/nsXPCOM_std18.pas b/components/geckoport/each-version/nsXPCOM_std18.pas
index fd899927f..89d0d24b0 100644
--- a/components/geckoport/each-version/nsXPCOM_std18.pas
+++ b/components/geckoport/each-version/nsXPCOM_std18.pas
@@ -8,6 +8,10 @@ unit nsXPCOM_std18;
   {$DEFINE extdecl:=cdecl}
 {$ENDIF}
 
+{$IFNDEF FPC_HAS_CONSTREF}
+  {$DEFINE constref:=const}
+{$ENDIF}
+
 interface
 
 uses
diff --git a/components/geckoport/each-version/nsXPCOM_std19.pas b/components/geckoport/each-version/nsXPCOM_std19.pas
index 0e334b81d..ad0745433 100644
--- a/components/geckoport/each-version/nsXPCOM_std19.pas
+++ b/components/geckoport/each-version/nsXPCOM_std19.pas
@@ -8,6 +8,10 @@ unit nsXPCOM_std19;
   {$DEFINE extdecl:=cdecl}
 {$ENDIF}
 
+{$IFNDEF FPC_HAS_CONSTREF}
+  {$DEFINE constref:=const}
+{$ENDIF}
+
 interface
 
 uses
diff --git a/components/geckoport/nsInit.pas b/components/geckoport/nsInit.pas
index b8fc9346f..6690ff4f4 100755
--- a/components/geckoport/nsInit.pas
+++ b/components/geckoport/nsInit.pas
@@ -42,6 +42,10 @@ unit nsInit;
   {$DEFINE extdecl:=cdecl}
 {$ENDIF}
 
+{$IFNDEF FPC_HAS_CONSTREF}
+  {$DEFINE constref:=const}
+{$ENDIF}
+
 interface
 
 uses
diff --git a/components/geckoport/nsXPCOM.pas b/components/geckoport/nsXPCOM.pas
index d35664819..0ad000fef 100644
--- a/components/geckoport/nsXPCOM.pas
+++ b/components/geckoport/nsXPCOM.pas
@@ -8,6 +8,10 @@ unit nsXPCOM;
   {$DEFINE extdecl:=cdecl}
 {$ENDIF}
 
+{$IFNDEF FPC_HAS_CONSTREF}
+  {$DEFINE constref:=const}
+{$ENDIF}
+
 interface
 
 uses
diff --git a/components/geckoport/nsXPCOMGlue.pas b/components/geckoport/nsXPCOMGlue.pas
index 885c0de3f..7224a2234 100644
--- a/components/geckoport/nsXPCOMGlue.pas
+++ b/components/geckoport/nsXPCOMGlue.pas
@@ -36,6 +36,12 @@
  * ***** END LICENSE BLOCK ***** *)
 unit nsXPCOMGlue;
 
+{$MACRO on}
+
+{$IFNDEF FPC_HAS_CONSTREF}
+  {$DEFINE constref:=const}
+{$ENDIF}
+
 interface
 
 uses