diff --git a/src/platform/apollolake/include/platform/lib/memory.h b/src/platform/apollolake/include/platform/lib/memory.h
index 953049b7c98c..396905f3a95a 100644
--- a/src/platform/apollolake/include/platform/lib/memory.h
+++ b/src/platform/apollolake/include/platform/lib/memory.h
@@ -309,7 +309,11 @@
 #define HEAP_SYSTEM_SHARED_SIZE		0x1500
 
 #define HEAP_BUFFER_BLOCK_SIZE	0x100
-#define HEAP_BUFFER_COUNT_MAX  (HP_SRAM_SIZE / HEAP_BUFFER_BLOCK_SIZE)
+/*
+ * The buffer zone will not occupy more than half of the HP SRAM on APL,
+ * enforcing this limit due to the the SRAM size limitations on APL.
+ */
+#define HEAP_BUFFER_COUNT_MAX  (HP_SRAM_SIZE / (HEAP_BUFFER_BLOCK_SIZE * 2))
 
 #define HEAP_SYSTEM_M_SIZE		0x4000	/* heap primary core size */
 #define HEAP_SYSTEM_S_SIZE		0x3000	/* heap secondary core size */
diff --git a/src/platform/library/include/platform/lib/memory.h b/src/platform/library/include/platform/lib/memory.h
index c81d44d99e26..f64118c03257 100644
--- a/src/platform/library/include/platform/lib/memory.h
+++ b/src/platform/library/include/platform/lib/memory.h
@@ -65,6 +65,7 @@ static inline uint32_t arch_get_stack_size(void)
 
 #define SRAM_BANK_SIZE	0x10000
 #define LP_SRAM_SIZE SRAM_BANK_SIZE
+/* use big enough HP_SRAM_SIZE to build all components for the test bench at once */
 #define HP_SRAM_SIZE (SRAM_BANK_SIZE * 47)
 
 #define HP_SRAM_BASE	0xBE000000
diff --git a/test/cmocka/src/lib/alloc/alloc.c b/test/cmocka/src/lib/alloc/alloc.c
index 16a472c7f32e..13c1fb4c2a35 100644
--- a/test/cmocka/src/lib/alloc/alloc.c
+++ b/test/cmocka/src/lib/alloc/alloc.c
@@ -200,8 +200,6 @@ static struct test_case test_cases[] = {
 		  2, TEST_BULK, "rballoc_dma"),
 	TEST_CASE(256, SOF_MEM_ZONE_BUFFER, SOF_MEM_CAPS_RAM | SOF_MEM_CAPS_DMA,
 		  2, TEST_BULK, "rballoc_dma"),
-	TEST_CASE(2048, SOF_MEM_ZONE_BUFFER, SOF_MEM_CAPS_RAM |
-		  SOF_MEM_CAPS_DMA, 100, TEST_IMMEDIATE_FREE, "rballoc_dma"),
 };
 
 static int setup(void **state)