diff --git a/pecoff.c b/pecoff.c
index 677e1cd..d4b86b0 100644
--- a/pecoff.c
+++ b/pecoff.c
@@ -595,7 +595,7 @@ coff_add (struct backtrace_state *state, int descriptor,
   const b_coff_section_header *sects;
   struct backtrace_view str_view;
   int str_view_valid;
-  size_t str_size;
+  uint32_t str_size;
   off_t str_off;
   struct backtrace_view syms_view = {0};
   off_t syms_off;