diff --git a/code/__DEFINES/flags.dm b/code/__DEFINES/flags.dm
index 2fe70961f8..d64fa30047 100644
--- a/code/__DEFINES/flags.dm
+++ b/code/__DEFINES/flags.dm
@@ -7,7 +7,7 @@
 //for convenience
 #define ENABLE_BITFIELD(variable, flag) (variable |= (flag))
 #define DISABLE_BITFIELD(variable, flag) (variable &= ~(flag))
-#define CHECK_BITFIELD(variable, flag) (variable & flag)
+#define CHECK_BITFIELD(variable, flag) (variable & (flag))
 #define TOGGLE_BITFIELD(variable, flag) (variable ^= (flag))
 
 GLOBAL_LIST_INIT(bitflags, list(1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768))