diff --git a/plat/arm/board/rde1edge/include/platform_def.h b/plat/arm/board/rde1edge/include/platform_def.h
index c39fe2b..a9b30a4 100644
--- a/plat/arm/board/rde1edge/include/platform_def.h
+++ b/plat/arm/board/rde1edge/include/platform_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020, Arm Limited. All rights reserved.
+ * Copyright (c) 2018-2021, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -9,6 +9,7 @@
 
 #include <lib/utils_def.h>
 
+#include <sgi_sdei.h>
 #include <sgi_soc_platform_def.h>
 
 #define PLAT_ARM_CLUSTER_COUNT		U(2)
diff --git a/plat/arm/board/rdn1edge/include/platform_def.h b/plat/arm/board/rdn1edge/include/platform_def.h
index b167c46..a61b0d5 100644
--- a/plat/arm/board/rdn1edge/include/platform_def.h
+++ b/plat/arm/board/rdn1edge/include/platform_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -9,6 +9,7 @@
 
 #include <lib/utils_def.h>
 
+#include <sgi_sdei.h>
 #include <sgi_soc_platform_def.h>
 
 #define PLAT_ARM_CLUSTER_COUNT		U(2)
diff --git a/plat/arm/board/sgi575/include/platform_def.h b/plat/arm/board/sgi575/include/platform_def.h
index c929334..72d5f7c 100644
--- a/plat/arm/board/sgi575/include/platform_def.h
+++ b/plat/arm/board/sgi575/include/platform_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -9,6 +9,7 @@
 
 #include <lib/utils_def.h>
 
+#include <sgi_sdei.h>
 #include <sgi_soc_platform_def.h>
 
 #define PLAT_ARM_CLUSTER_COUNT		U(2)
diff --git a/plat/arm/css/sgi/include/sgi_base_platform_def.h b/plat/arm/css/sgi/include/sgi_base_platform_def.h
index b805746..d99ea3b 100644
--- a/plat/arm/css/sgi/include/sgi_base_platform_def.h
+++ b/plat/arm/css/sgi/include/sgi_base_platform_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2021, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -183,16 +183,6 @@
 #define SP_DMC_ERROR_ECC_EVENT_AARCH64		0xC4000044
 #define SP_DMC_ERROR_ECC_EVENT_AARCH32		0x84000044
 
-/* ARM SDEI dynamic shared event numbers */
-#define SGI_SDEI_DS_EVENT_0			804
-#define SGI_SDEI_DS_EVENT_1			805
-
-#define PLAT_ARM_PRIVATE_SDEI_EVENTS	\
-	SDEI_DEFINE_EVENT_0(ARM_SDEI_SGI), \
-	SDEI_EXPLICIT_EVENT(SGI_SDEI_DS_EVENT_0, SDEI_MAPF_CRITICAL), \
-	SDEI_EXPLICIT_EVENT(SGI_SDEI_DS_EVENT_1, SDEI_MAPF_CRITICAL),
-#define PLAT_ARM_SHARED_SDEI_EVENTS
-
 #define ARM_SP_CPER_BUF_BASE			(PLAT_SP_IMAGE_NS_BUF_BASE + \
 						PLAT_SP_IMAGE_NS_BUF_SIZE)
 #define ARM_SP_CPER_BUF_SIZE			ULL(0x20000)
diff --git a/plat/arm/css/sgi/include/sgi_sdei.h b/plat/arm/css/sgi/include/sgi_sdei.h
new file mode 100644
index 0000000..f380122
--- /dev/null
+++ b/plat/arm/css/sgi/include/sgi_sdei.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2021, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef SGI_SDEI_H
+#define SGI_SDEI_H
+
+#if SDEI_SUPPORT
+
+/* ARM SDEI dynamic shared event numbers */
+#define SGI_SDEI_DS_EVENT_0		U(804)
+#define SGI_SDEI_DS_EVENT_1		U(805)
+
+#define PLAT_ARM_PRIVATE_SDEI_EVENTS					      \
+		SDEI_DEFINE_EVENT_0(ARM_SDEI_SGI),			      \
+		SDEI_EXPLICIT_EVENT(SGI_SDEI_DS_EVENT_0, SDEI_MAPF_CRITICAL), \
+		SDEI_EXPLICIT_EVENT(SGI_SDEI_DS_EVENT_1, SDEI_MAPF_CRITICAL),
+
+#define PLAT_ARM_SHARED_SDEI_EVENTS
+
+#endif /* SDEI_SUPPORT */
+
+#endif /* SGI_SDEI_H */