diff --git a/ChangeLog b/ChangeLog
index 2d4290da1..e497d8c2a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2005-07-28  Owen Taylor  <otaylor@redhat.com>
+
+	* src/cairo-image-surface.c (_cairo_image_surface_acquire_source,dest_image) 
+	src/cairo-quartz-surface.c (_cairo_quartz_surface_acquire_dest_image)
+	src/cairo-xcb-surface.c (_cairo_xcb_surface_acquire_source,dest_image): 
+	src/cairo-xlib-surface.c (_cairo_xlib_surface_acquire_source,dest_image): 
+	Set image_extra to NULL to avoid purify warnings. (#3777, Stuart Parmenter)
+
 2005-07-27  Carl Worth  <cworth@cworth.org>
 
 	* src/cairoint.h:
diff --git a/src/cairo-image-surface.c b/src/cairo-image-surface.c
index 4d0a3d319..59734e4aa 100644
--- a/src/cairo-image-surface.c
+++ b/src/cairo-image-surface.c
@@ -349,6 +349,7 @@ _cairo_image_surface_acquire_source_image (void                    *abstract_sur
 					   void                   **image_extra)
 {
     *image_out = abstract_surface;
+    *image_extra = NULL;
     
     return CAIRO_STATUS_SUCCESS;
 }
@@ -375,7 +376,8 @@ _cairo_image_surface_acquire_dest_image (void                    *abstract_surfa
     image_rect_out->height = surface->height;
 
     *image_out = surface;
-
+    *image_extra = NULL;
+    
     return CAIRO_STATUS_SUCCESS;
 }
 
diff --git a/src/cairo-quartz-surface.c b/src/cairo-quartz-surface.c
index 092c0cd0d..af92c0104 100644
--- a/src/cairo-quartz-surface.c
+++ b/src/cairo-quartz-surface.c
@@ -152,6 +152,7 @@ _cairo_quartz_surface_acquire_dest_image(void *abstract_surface,
     image_rect->height = surface->image->height;
 
     *image_out = surface->image;
+    *image_extra = NULL;
 
     return CAIRO_STATUS_SUCCESS;
 }
diff --git a/src/cairo-xcb-surface.c b/src/cairo-xcb-surface.c
index 40a4ec835..04f5892ed 100644
--- a/src/cairo-xcb-surface.c
+++ b/src/cairo-xcb-surface.c
@@ -582,6 +582,7 @@ _cairo_xcb_surface_acquire_source_image (void                    *abstract_surfa
 	return status;
 
     *image_out = image;
+    *image_extra = NULL;
 
     return CAIRO_STATUS_SUCCESS;
 }
@@ -610,6 +611,7 @@ _cairo_xcb_surface_acquire_dest_image (void                    *abstract_surface
 	return status;
 
     *image_out = image;
+    *image_extra = NULL;
 
     return CAIRO_STATUS_SUCCESS;
 }
diff --git a/src/cairo-xlib-surface.c b/src/cairo-xlib-surface.c
index a9b20a2c9..39d101014 100644
--- a/src/cairo-xlib-surface.c
+++ b/src/cairo-xlib-surface.c
@@ -589,6 +589,7 @@ _cairo_xlib_surface_acquire_source_image (void                    *abstract_surf
 	return status;
 
     *image_out = image;
+    *image_extra = NULL;
 
     return CAIRO_STATUS_SUCCESS;
 }
@@ -617,7 +618,8 @@ _cairo_xlib_surface_acquire_dest_image (void                    *abstract_surfac
 	return status;
 
     *image_out = image;
-
+    *image_extra = NULL;
+    
     return CAIRO_STATUS_SUCCESS;
 }