diff --git a/trick_sims/SIM_cannon_aero/S_overrides.mk b/trick_sims/SIM_cannon_aero/S_overrides.mk
index 086e38ff..20183fb2 100644
--- a/trick_sims/SIM_cannon_aero/S_overrides.mk
+++ b/trick_sims/SIM_cannon_aero/S_overrides.mk
@@ -1,2 +1,5 @@
+ifndef TRICK_HOME
+    $(error TRICK_HOME environment variable is not set. Please set it and retry.)
+endif
 TRICK_CFLAGS += -I${TRICK_HOME}/trick_models
 TRICK_CXXFLAGS += -I${TRICK_HOME}/trick_models