diff --git a/packages/cultmath/tools/glsl/spvedit.py b/packages/cultmath/tools/glsl/spvedit.py
index d1b3e169..5d882b13 100644
--- a/packages/cultmath/tools/glsl/spvedit.py
+++ b/packages/cultmath/tools/glsl/spvedit.py
@@ -14,7 +14,7 @@ import struct, sys
 
 OP_NAME, OP_MEMBER_NAME, OP_CAPABILITY, OP_EXTENSION, OP_DECORATE, OP_MEMBER_DECORATE = 5, 6, 17, 10, 71, 72
 OP_TYPE_ARRAY, OP_CONSTANT, OP_SPEC_CONSTANT, DECORATION_SPEC_ID = 28, 43, 50, 1
-SPEC_ID = 0
+SPEC_ID = int.from_bytes(b'CMS1', 'big')     # CultMath's own id: a consumer's SPIRV_CROSS_CONSTANT_ID_n macro cannot meet it
 OP_TYPE_POINTER, OP_TYPE_FUNCTION, OP_FUNCTION, OP_PARAMETER, OP_FUNCTION_END = 32, 33, 54, 55, 56
 OP_CALL, OP_LABEL, OP_VARIABLE, OP_LOAD, OP_STORE = 57, 248, 59, 61, 62
 CAP_SHADER, CAP_LINKAGE, DECORATION_LINKAGE, LINKAGE_EXPORT, FUNCTION_STORAGE = 1, 5, 41, 41, 7