diff --git a/gfx/src/gtk/nsPrintdGTK.h b/gfx/src/gtk/nsPrintdGTK.h
index a68540e833d5..29b1c436623c 100644
--- a/gfx/src/gtk/nsPrintdGTK.h
+++ b/gfx/src/gtk/nsPrintdGTK.h
@@ -18,8 +18,13 @@
 
 /* Original Code: Syd Logan (syd@netscape.com) 3/12/99 */
 
+#ifndef nsPrintdGTK_h___
+#define nsPrintdGTK_h___
+
 #include <limits.h>
 
+PR_BEGIN_EXTERN_C
+
 /* stolen from nsPostScriptObj.h. needs to be put somewhere else that
    both ps and gtk can see easily */
 
@@ -44,3 +49,8 @@ typedef struct unixprdata {
 	float bottom;		    /* bottom margin */
 } UnixPrData;
 
+void UnixPrDialog(UnixPrData *prData);
+
+PR_END_EXTERN_C
+
+#endif /* nsPrintdGTK_h___ */
diff --git a/widget/src/gtk2/nsPrintdGTK.h b/widget/src/gtk2/nsPrintdGTK.h
index a68540e833d5..29b1c436623c 100644
--- a/widget/src/gtk2/nsPrintdGTK.h
+++ b/widget/src/gtk2/nsPrintdGTK.h
@@ -18,8 +18,13 @@
 
 /* Original Code: Syd Logan (syd@netscape.com) 3/12/99 */
 
+#ifndef nsPrintdGTK_h___
+#define nsPrintdGTK_h___
+
 #include <limits.h>
 
+PR_BEGIN_EXTERN_C
+
 /* stolen from nsPostScriptObj.h. needs to be put somewhere else that
    both ps and gtk can see easily */
 
@@ -44,3 +49,8 @@ typedef struct unixprdata {
 	float bottom;		    /* bottom margin */
 } UnixPrData;
 
+void UnixPrDialog(UnixPrData *prData);
+
+PR_END_EXTERN_C
+
+#endif /* nsPrintdGTK_h___ */