diff --git a/include/compartment.h b/include/compartment.h
index b0415fd..bf35f58 100644
--- a/include/compartment.h
+++ b/include/compartment.h
@@ -129,7 +129,7 @@ struct LibDependency
     // TLS-related variables
     // TODO can there be more TLS sections?
     void *tls_sec_addr;
-    ptrdiff_t tls_sec_off;
+    size_t tls_sec_off;
     size_t tls_sec_size;
     size_t tls_data_size;
     // offset from TLS base pointer (i.e., value of `tpidr_el0`) where this