diff --git a/src/detection/memory/memory_apple.c b/src/detection/memory/memory_apple.c
index cabdab267d..190ff98d5a 100644
--- a/src/detection/memory/memory_apple.c
+++ b/src/detection/memory/memory_apple.c
@@ -16,15 +16,12 @@ const char* ffDetectMemory(FFMemoryResult* ram)
     if(host_statistics64(mach_host_self(), HOST_VM_INFO64, (host_info64_t) (&vmstat), &count) != KERN_SUCCESS)
         return "Failed to read host_statistics64";
 
-    // https://github.com/exelban/stats/blob/master/Modules/RAM/readers.swift#L56
+    // https://github.com/apple-opensource/top/blob/e7979606cf63270663a62cfe69f82d35cef9ba58/globalstats.c#L433-L435
     ram->bytesUsed = ((uint64_t)
-        + vmstat.active_count
-        + vmstat.inactive_count
-        + vmstat.speculative_count
-        + vmstat.wire_count
+        + vmstat.wire_count 
+        + vmstat.inactive_count 
+        + vmstat.active_count 
         + vmstat.compressor_page_count
-        - vmstat.purgeable_count
-        - vmstat.external_page_count
     ) * instance.state.platform.sysinfo.pageSize;
 
     return NULL;