diff --git a/renderdoc/driver/shaders/spirv/spirv_disassemble.cpp b/renderdoc/driver/shaders/spirv/spirv_disassemble.cpp
index 3b14e9a6a..31ffcd2d6 100644
--- a/renderdoc/driver/shaders/spirv/spirv_disassemble.cpp
+++ b/renderdoc/driver/shaders/spirv/spirv_disassemble.cpp
@@ -4033,7 +4033,7 @@ void ParseSPIRV(uint32_t *spirv, size_t spirvLength, SPVModule &module)
 
 				// const argument bitfield
 				uint32_t imMask = 0;
-				if(WordCount > 5)
+				if(WordCount > idx)
 				{
 					imMask = spirv[it+idx];
 					idx++;