diff --git a/lib/fprotect/fprotect_spu.c b/lib/fprotect/fprotect_spu.c
index d2aafd5b9..811358d10 100644
--- a/lib/fprotect/fprotect_spu.c
+++ b/lib/fprotect/fprotect_spu.c
@@ -12,7 +12,12 @@
 #include <nrf_erratas.h>
 
 
+#if defined(CONFIG_SOC_NRF5340_CPUAPP) \
+	&& defined(CONFIG_NRF5340_CPUAPP_ERRATUM19)
+#define SPU_BLOCK_SIZE (nrf53_errata_19() ? 32*1024 : 16*1024)
+#else
 #define SPU_BLOCK_SIZE CONFIG_FPROTECT_BLOCK_SIZE
+#endif
 
 int fprotect_area(uint32_t start, size_t length)
 {
diff --git a/subsys/spm/spm_internal.h b/subsys/spm/spm_internal.h
index 426fe6e38..3d25b43fb 100644
--- a/subsys/spm/spm_internal.h
+++ b/subsys/spm/spm_internal.h
@@ -31,6 +31,15 @@ extern "C" {
 				/ RAM_SECURE_ATTRIBUTION_REGION_SIZE)
 
 /* SPU FLASH regions */
+#if (defined(CONFIG_SOC_NRF5340_CPUAPP) \
+	&& defined(CONFIG_NRF5340_CPUAPP_ERRATUM19))
+
+#define FLASH_SECURE_ATTRIBUTION_REGION_SIZE \
+				(nrf53_errata_19() ? 32*1024 : 16*1024)
+#define NUM_FLASH_SECURE_ATTRIBUTION_REGIONS (nrf53_errata_19() ? 32 : 64)
+#else
+
+
 #define SOC_NV_FLASH_NODE DT_INST(0, soc_nv_flash)
 #define SOC_NV_FLASH_SIZE DT_REG_SIZE(SOC_NV_FLASH_NODE)
 
@@ -38,6 +47,8 @@ extern "C" {
 #define NUM_FLASH_SECURE_ATTRIBUTION_REGIONS (SOC_NV_FLASH_SIZE \
 				/ FLASH_SECURE_ATTRIBUTION_REGION_SIZE)
 
+#endif
+
 /* Minimum size of Non-Secure Callable regions. */
 #define FLASH_NSC_MIN_SIZE 32