diff --git a/build/jam/BuildSetup b/build/jam/BuildSetup
index c59049d428..1d0752d7f9 100644
--- a/build/jam/BuildSetup
+++ b/build/jam/BuildSetup
@@ -839,6 +839,10 @@ OPTIM ?= -O2 ;
 DEBUG ?= 0 ;
 
 
+# Set a sane default for whether this is a CI build.
+HAIKU_CONTINUOUS_INTEGRATION_BUILD ?= 0 ;
+
+
 # Set the defaults for PLATFORM and SUPPORTED_PLATFORMS. PLATFORM is only
 # overridden for targets to be built for the host platform. SUPPORTED_PLATFORMS
 # can be overridden by the author of a component.