diff --git a/scripts/xtensa-build-zephyr.sh b/scripts/xtensa-build-zephyr.sh
index 3b24c087e674..3b09cba0c940 100755
--- a/scripts/xtensa-build-zephyr.sh
+++ b/scripts/xtensa-build-zephyr.sh
@@ -150,11 +150,8 @@ build_all()
 		case "$platform" in
 			apl)
 				PLAT_CONFIG='intel_adsp_cavs15'
-				# XCC build runs out of memory, tracked as
-				# https://github.com/thesofproject/sof/issues/4645
-				unset XTENSA_TOOLS_ROOT
-				#XTENSA_CORE="X4H3I16w2D48w3a_2017_8"
-				#XTENSA_TOOLS_VERSION="RG-2017.8-linux"
+				XTENSA_CORE="X4H3I16w2D48w3a_2017_8"
+				XTENSA_TOOLS_VERSION="RG-2017.8-linux"
 				;;
 			cnl)
 				PLAT_CONFIG='intel_adsp_cavs18'
diff --git a/zephyr/wrapper.c b/zephyr/wrapper.c
index 1bbe36fd025a..c630b7c6500b 100644
--- a/zephyr/wrapper.c
+++ b/zephyr/wrapper.c
@@ -80,7 +80,11 @@ __section(".heap_mem") static uint8_t __aligned(64) heapmem[HEAPMEM_SIZE];
  */
 #if (CONFIG_HP_MEMORY_BANKS < 16)
 /* e.g. APL */
+#if defined __XCC__
+#define	HEAP_SIZE	0x28000
+#else
 #define	HEAP_SIZE	0x30000
+#endif
 #elif (CONFIG_HP_MEMORY_BANKS < 30)
 /* e.g. JSL */
 #define	HEAP_SIZE	0x80000