diff --git a/include/plat/arm/css/common/css_def.h b/include/plat/arm/css/common/css_def.h
index a2fe0d5..7cfaf59 100644
--- a/include/plat/arm/css/common/css_def.h
+++ b/include/plat/arm/css/common/css_def.h
@@ -101,6 +101,13 @@
 #define SSC_VERSION_DESIGNER_ID_MASK		0xff
 #define SSC_VERSION_PART_NUM_MASK		0xfff
 
+/* SSC debug configuration registers */
+#define SSC_DBGCFG_SET		0x14
+#define SSC_DBGCFG_CLR		0x18
+
+#define SPIDEN_INT_CLR_SHIFT	6
+#define SPIDEN_SEL_SET_SHIFT	7
+
 #ifndef __ASSEMBLY__
 
 /* SSC_VERSION related accessors */
diff --git a/plat/arm/board/juno/juno_security.c b/plat/arm/board/juno/juno_security.c
index 202342a..70637d6 100644
--- a/plat/arm/board/juno/juno_security.c
+++ b/plat/arm/board/juno/juno_security.c
@@ -60,16 +60,34 @@
 }
 
 /*******************************************************************************
+ * Initialize debug configuration.
+ ******************************************************************************/
+static void init_debug_cfg(void)
+{
+#if !DEBUG
+	/* Set internal drive selection for SPIDEN. */
+	mmio_write_32(SSC_REG_BASE + SSC_DBGCFG_SET,
+		1U << SPIDEN_SEL_SET_SHIFT);
+
+	/* Drive SPIDEN LOW to disable invasive debug of secure state. */
+	mmio_write_32(SSC_REG_BASE + SSC_DBGCFG_CLR,
+		1U << SPIDEN_INT_CLR_SHIFT);
+#endif
+}
+
+/*******************************************************************************
  * Initialize the secure environment.
  ******************************************************************************/
 void plat_arm_security_setup(void)
 {
+	/* Initialize debug configuration */
+	init_debug_cfg();
 	/* Initialize the TrustZone Controller */
 	arm_tzc400_setup();
 	/* Do ARM CSS internal NIC setup */
 	css_init_nic400();
 	/* Do ARM CSS SoC security setup */
 	soc_css_security_setup();
-	/* Initialize the SMMU SSD tables*/
+	/* Initialize the SMMU SSD tables */
 	init_mmu401();
 }