diff --git a/src/activity.c b/src/activity.c
index b5fac8841..b48f4b43b 100644
--- a/src/activity.c
+++ b/src/activity.c
@@ -23,7 +23,7 @@
 
 
 /* bit field of profiling options. Beware, may be modified at runtime! */
-unsigned int profiling;
+unsigned int profiling = 0;
 
 /* One struct per thread containing all collected measurements */
 struct activity activity[MAX_THREADS] __attribute__((aligned(64))) = { };