diff --git a/boards/arm/particle_argon/board.c b/boards/arm/particle_argon/board.c
index a6d559cb34023a..d9a2311c49efa0 100644
--- a/boards/arm/particle_argon/board.c
+++ b/boards/arm/particle_argon/board.c
@@ -49,6 +49,7 @@ static int board_particle_argon_init(const struct device *dev)
 	return 0;
 }
 
-/* needs to be done after GPIO driver init */
-SYS_INIT(board_particle_argon_init, POST_KERNEL,
-	 CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
+/* needs to be done after GPIO driver init, which is at
+ * POST_KERNEL:KERNEL_INIT_PRIORITY_DEFAULT.
+ */
+SYS_INIT(board_particle_argon_init, POST_KERNEL, 99);
diff --git a/boards/arm/particle_boron/board.c b/boards/arm/particle_boron/board.c
index 0e5714a3efa555..a77c3e7d6a3231 100644
--- a/boards/arm/particle_boron/board.c
+++ b/boards/arm/particle_boron/board.c
@@ -56,6 +56,7 @@ static int board_particle_boron_init(const struct device *dev)
 	return 0;
 }
 
-/* needs to be done after GPIO driver init */
-SYS_INIT(board_particle_boron_init, POST_KERNEL,
-	 CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
+/* needs to be done after GPIO driver init, which is at
+ * POST_KERNEL:KERNEL_INIT_PRIORITY_DEFAULT.
+ */
+SYS_INIT(board_particle_boron_init, POST_KERNEL, 99);
diff --git a/boards/arm/particle_xenon/board.c b/boards/arm/particle_xenon/board.c
index dc10fdcc08ced8..9844941294796c 100644
--- a/boards/arm/particle_xenon/board.c
+++ b/boards/arm/particle_xenon/board.c
@@ -49,6 +49,7 @@ static int board_particle_xenon_init(const struct device *dev)
 	return 0;
 }
 
-/* needs to be done after GPIO driver init */
-SYS_INIT(board_particle_xenon_init, POST_KERNEL,
-	 CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);
+/* needs to be done after GPIO driver init, which is at
+ * POST_KERNEL:KERNEL_INIT_PRIORITY_DEFAULT.
+ */
+SYS_INIT(board_particle_xenon_init, POST_KERNEL, 99);