diff --git a/sim/meson.build b/sim/meson.build
index 3693e81..fe3fa32 100644
--- a/sim/meson.build
+++ b/sim/meson.build
@@ -1,7 +1,7 @@
 tests = ['openpower-libhei-sim']
 
 sim_sources = ['hei_sim_main.cpp',
-                '../hei_isolator.cpp']
+                '../src/hei_isolator.cpp']
 
 foreach t : tests
   test(t, executable(t.underscorify(), sim_sources, include_directories : incdir))