diff --git a/jerry-core/jmem/jmem-heap.c b/jerry-core/jmem/jmem-heap.c
index f93e82f2f..a2b9c9d0f 100644
--- a/jerry-core/jmem/jmem-heap.c
+++ b/jerry-core/jmem/jmem-heap.c
@@ -649,7 +649,15 @@ jmem_heap_realloc_block (void *ptr, /**< memory region to reallocate */
   JMEM_HEAP_STAT_ALLOC (new_size);
   return ret_block_p;
 #else /* ENABLED (JERRY_SYSTEM_ALLOCATOR) */
-  JERRY_CONTEXT (jmem_heap_allocated_size) += (new_size - old_size);
+  const size_t required_size = new_size - old_size;
+#if !ENABLED (JERRY_MEM_GC_BEFORE_EACH_ALLOC)
+  if (JERRY_CONTEXT (jmem_heap_allocated_size) + required_size >= JERRY_CONTEXT (jmem_heap_limit))
+#endif /* !ENABLED (JERRY_MEM_GC_BEFORE_EACH_ALLOC) */
+  {
+    ecma_free_unused_memory (JMEM_PRESSURE_LOW);
+  }
+
+  JERRY_CONTEXT (jmem_heap_allocated_size) += required_size;
 
   while (JERRY_CONTEXT (jmem_heap_allocated_size) >= JERRY_CONTEXT (jmem_heap_limit))
   {