diff --git a/rtos/tests/TESTS/mbed_rtos/malloc/main.cpp b/rtos/tests/TESTS/mbed_rtos/malloc/main.cpp
index a470547e2d7..70aece1946e 100644
--- a/rtos/tests/TESTS/mbed_rtos/malloc/main.cpp
+++ b/rtos/tests/TESTS/mbed_rtos/malloc/main.cpp
@@ -106,7 +106,7 @@ void test_multithread_allocation(void)
 #endif
 
 /** Test for multiple heap alloc and free calls */
-#define ALLOC_ARRAY_SIZE    100
+#define ALLOC_ARRAY_SIZE    50
 #define ALLOC_LOOP          20
 #define SIZE_INCREMENTS     1023
 #define SIZE_MODULO         31