diff --git a/backend/dc210.c b/backend/dc210.c
index 83e1d7568..d0ceef8a9 100644
--- a/backend/dc210.c
+++ b/backend/dc210.c
@@ -167,7 +167,7 @@ static SANE_Option_Descriptor sod[] = {
    4,
    SANE_CAP_SOFT_SELECT | SANE_CAP_SOFT_DETECT,
    SANE_CONSTRAINT_RANGE,
-   {(SANE_String_Const *) & image_range}	/* this is ANSI conformant! */
+   {(void *) & image_range}
    }
   ,
 
@@ -653,7 +653,7 @@ change_res (int fd, unsigned char res)
 }
 
 SANE_Status
-sane_init (SANE_Int * version_code, SANE_Auth_Callback UNUSEDARG authorize)
+sane_init (SANE_Int * version_code, SANE_Auth_Callback __unused__ authorize)
 {
 
   char f[] = "sane_init";
@@ -826,7 +826,7 @@ static const SANE_Device dev[] = {
 
 SANE_Status
 sane_get_devices (const SANE_Device *** device_list,
-		  SANE_Bool UNUSEDARG local_only)
+		  SANE_Bool __unused__ local_only)
 {
   static const SANE_Device *devlist[] = {
     dev + 0, 0
@@ -1127,7 +1127,7 @@ my_source_mgr;
 typedef my_source_mgr *my_src_ptr;
 
 METHODDEF (void)
-sanei_jpeg_init_source (j_decompress_ptr UNUSEDARG cinfo)
+sanei_jpeg_init_source (j_decompress_ptr __unused__ cinfo)
 {
   /* nothing to do */
 }
@@ -1169,7 +1169,7 @@ sanei_jpeg_skip_input_data (j_decompress_ptr cinfo, long num_bytes)
 }
 
 METHODDEF (void)
-sanei_jpeg_term_source (j_decompress_ptr UNUSEDARG cinfo)
+sanei_jpeg_term_source (j_decompress_ptr __unused__ cinfo)
 {
   /* no work necessary here */
 }
@@ -1274,7 +1274,7 @@ sane_start (SANE_Handle handle)
 }
 
 SANE_Status
-sane_read (SANE_Handle UNUSEDARG handle, SANE_Byte * data,
+sane_read (SANE_Handle __unused__ handle, SANE_Byte * data,
 	   SANE_Int max_length, SANE_Int * length)
 {
 
@@ -1377,7 +1377,7 @@ sane_read (SANE_Handle UNUSEDARG handle, SANE_Byte * data,
 }
 
 void
-sane_cancel (SANE_Handle UNUSEDARG handle)
+sane_cancel (SANE_Handle __unused__ handle)
 {
   DBG (127, "sane_cancel() called\n");
   if (Camera.scanning)
@@ -1387,14 +1387,14 @@ sane_cancel (SANE_Handle UNUSEDARG handle)
 }
 
 SANE_Status
-sane_set_io_mode (SANE_Handle UNUSEDARG handle,
-		  SANE_Bool UNUSEDARG non_blocking)
+sane_set_io_mode (SANE_Handle __unused__ handle,
+		  SANE_Bool __unused__ non_blocking)
 {
   return SANE_STATUS_UNSUPPORTED;
 }
 
 SANE_Status
-sane_get_select_fd (SANE_Handle UNUSEDARG handle, SANE_Int * UNUSEDARG fd)
+sane_get_select_fd (SANE_Handle __unused__ handle, SANE_Int __unused__ * fd)
 {
   return SANE_STATUS_UNSUPPORTED;
 }
diff --git a/backend/dc210.h b/backend/dc210.h
index b47ff3723..fe2b6334f 100644
--- a/backend/dc210.h
+++ b/backend/dc210.h
@@ -76,12 +76,6 @@
 #define NULL	0L
 #endif
 
-#ifdef __GNUC__
-#define UNUSEDARG __attribute__ ((unused))
-#else
-#define UNUSEDARG
-#endif
-
 typedef struct picture_info
   {
     unsigned int low_res;