diff --git a/neo/idlib/Heap.h b/neo/idlib/Heap.h
index db17a95f..36c2c925 100644
--- a/neo/idlib/Heap.h
+++ b/neo/idlib/Heap.h
@@ -142,6 +142,24 @@ __inline void operator delete[]( void *p ) {
 #endif /* ID_DEBUG_MEMORY */
 
 
+// allocate SIZE bytes, aligned to 16 bytes - possibly on the stack (like _alloca16())
+// if it's too big (> ID_MAX_ALLOCA_SIZE, 1MB), it gets allocated on the Heap instead.
+// ON_STACK should be a bool and will be set to true if it was allocated on the stack
+// and false if it was allocated on the heap.
+// if ON_STACK is false, you must free this with Mem_FreeA() or Mem_Free16()!
+// (just pass your ON_STACK bool to Mem_FreeA() and it will do the right thing)
+#define Mem_MallocA( SIZE, ON_STACK ) \
+	( (SIZE) < ID_MAX_ALLOCA_SIZE ? ( ON_STACK=true, _alloca16(SIZE) ) : ( ON_STACK=false, Mem_Alloc16(SIZE) ) )
+
+// free memory allocated with Mem_MallocA()
+ID_INLINE void Mem_FreeA( void* ptr, bool onStack )
+{
+	if( !onStack ) {
+		Mem_Free16( ptr );
+	}
+}
+
+
 /*
 ===============================================================================
 
diff --git a/neo/sys/platform.h b/neo/sys/platform.h
index 7e936ffa..567c8326 100644
--- a/neo/sys/platform.h
+++ b/neo/sys/platform.h
@@ -38,9 +38,11 @@ If you have questions concerning this license or the applicable additional terms
 
 // NOTE: By default Win32 uses a 1MB stack. Doom3 1.3.1 uses 4MB (probably set after compiling with EDITBIN /STACK
 // dhewm3 now uses a 8MB stack, set with a linker flag in CMakeLists.txt (/STACK:8388608 for MSVC, -Wl,--stack,8388608 for mingw)
-// Linux has a 8MB stack by default, and so does macOS, at least for the main thread
-// anyway, a 2MB limit alloca should be safe even when using it multiple times in the same function
-#define ID_MAX_ALLOCA_SIZE 2097152 // 2MB
+// Linux has a 8MB stack by default, and so does macOS, at least for the main thread.
+// Anyway, a 1MB limit for _alloca() should be safe even when using it multiple times
+// in the same function or callstack.
+// If there's a risk of bigger stack allocations, Mem_MallocA() should be used instead.
+#define ID_MAX_ALLOCA_SIZE 1048576 // 1MB
 
 /*
 ===============================================================================