diff --git a/contrib/kyua/engine/atf.cpp b/contrib/kyua/engine/atf.cpp
index f6746dd2f29..47f3bd2a190 100644
--- a/contrib/kyua/engine/atf.cpp
+++ b/contrib/kyua/engine/atf.cpp
@@ -196,6 +196,7 @@ engine::atf_interface::exec_test(const model::test_program& test_program,
     auto e = execenv::get(test_program, test_case_name);
     e->init();
     e->exec(args);
+    __builtin_unreachable();
 }
 
 
@@ -227,6 +228,7 @@ engine::atf_interface::exec_cleanup(
 
     auto e = execenv::get(test_program, test_case_name);
     e->exec(args);
+    __builtin_unreachable();
 }
 
 
diff --git a/contrib/kyua/engine/plain.cpp b/contrib/kyua/engine/plain.cpp
index 9a2c63f8b66..0aba9b3fb6f 100644
--- a/contrib/kyua/engine/plain.cpp
+++ b/contrib/kyua/engine/plain.cpp
@@ -110,6 +110,7 @@ engine::plain_interface::exec_test(
     auto e = execenv::get(test_program, test_case_name);
     e->init();
     e->exec(args);
+    __builtin_unreachable();
 }
 
 
diff --git a/contrib/kyua/engine/tap.cpp b/contrib/kyua/engine/tap.cpp
index ed35ba40433..716212d18d0 100644
--- a/contrib/kyua/engine/tap.cpp
+++ b/contrib/kyua/engine/tap.cpp
@@ -157,6 +157,7 @@ engine::tap_interface::exec_test(
     auto e = execenv::get(test_program, test_case_name);
     e->init();
     e->exec(args);
+    __builtin_unreachable();
 }