diff --git a/src/heap_useNewlib_ST.c b/src/heap_useNewlib_ST.c
index b56419c..4639e6c 100644
--- a/src/heap_useNewlib_ST.c
+++ b/src/heap_useNewlib_ST.c
@@ -67,6 +67,16 @@
 #include <sta/config.hpp>
 #ifdef STA_RTOS_MALLOC_ENABLE
 
+// Allow setting configISR_STACK_SIZE_WORDS via the STA_RTOS_ISR_STACK_SIZE_WORDS config macro
+#ifdef STA_RTOS_ISR_STACK_SIZE_WORDS
+#  ifdef configISR_STACK_SIZE_WORDS
+#    warning "STA_RTOS_ISR_STACK_SIZE_WORDS value overriden by configISR_STACK_SIZE_WORDS!"
+#  else // configISR_STACK_SIZE_WORDS
+#    define configISR_STACK_SIZE_WORDS STA_RTOS_ISR_STACK_SIZE_WORDS
+#  endif // configISR_STACK_SIZE_WORDS
+#endif // STA_RTOS_ISR_STACK_SIZE_WORDS
+
+
 // ================================================================================================
 // =======================================  Configuration  ========================================
 // These configuration symbols could be provided by from build...