diff --git a/dlls/msi/string.c b/dlls/msi/string.c
index 3bdc436..84f4e71 100644
--- a/dlls/msi/string.c
+++ b/dlls/msi/string.c
@@ -44,8 +44,8 @@
 
 typedef struct _msistring
 {
-    UINT persistent_refcount;
-    UINT nonpersistent_refcount;
+    USHORT persistent_refcount;
+    USHORT nonpersistent_refcount;
     LPWSTR str;
 } msistring;
 
@@ -188,7 +188,7 @@
     st->sortcount++;
 }
 
-static void set_st_entry( string_table *st, UINT n, LPWSTR str, UINT refcount, enum StringPersistence persistence )
+static void set_st_entry( string_table *st, UINT n, LPWSTR str, USHORT refcount, enum StringPersistence persistence )
 {
     if (persistence == StringPersistent)
     {
@@ -237,7 +237,7 @@
     return r;
 }
 
-static int msi_addstring( string_table *st, UINT n, const CHAR *data, int len, UINT refcount, enum StringPersistence persistence )
+static int msi_addstring( string_table *st, UINT n, const CHAR *data, int len, USHORT refcount, enum StringPersistence persistence )
 {
     LPWSTR str;
     int sz;
@@ -288,7 +288,7 @@
     return n;
 }
 
-int msi_addstringW( string_table *st, UINT n, const WCHAR *data, int len, UINT refcount, enum StringPersistence persistence )
+int msi_addstringW( string_table *st, UINT n, const WCHAR *data, int len, USHORT refcount, enum StringPersistence persistence )
 {
     LPWSTR str;