diff --git a/src/frontend/inp.c b/src/frontend/inp.c
index 90fdd0f61..f2f0c5a64 100644
--- a/src/frontend/inp.c
+++ b/src/frontend/inp.c
@@ -1055,8 +1055,11 @@ inp_dodeck(
     ct->ci_inprogress = FALSE;
     ct->ci_runonce = FALSE;
     ct->ci_commands = end;
+    /* prevent false reads in multi-threaded ngshared */
+#ifndef SHARED_MODULE
     if (reuse)
         tfree(ct->ci_filename);
+#endif
     ct->ci_filename = copy(filename);
 
     if (!noparse) {