diff --git a/psrdada_cpp/effelsberg/edd/GatedSpectrometer.cuh b/psrdada_cpp/effelsberg/edd/GatedSpectrometer.cuh
index 44ade0a2ce75deed2a6fe755467eed48d3ffa567..4bd3cc5addc50755c1fc4f29b2a55f3b5f15be39 100644
--- a/psrdada_cpp/effelsberg/edd/GatedSpectrometer.cuh
+++ b/psrdada_cpp/effelsberg/edd/GatedSpectrometer.cuh
@@ -19,7 +19,7 @@ namespace effelsberg {
 namespace edd {
 
 
-#define BIT_MASK(bit) (1L << (bit))
+#define BIT_MASK(bit) (1uL << (bit))
 #define SET_BIT(value, bit) ((value) |= BIT_MASK(bit))
 #define CLEAR_BIT(value, bit) ((value) &= ~BIT_MASK(bit))
 #define TEST_BIT(value, bit) (((value)&BIT_MASK(bit)) ? 1 : 0)