diff --git a/server/atom.c b/server/atom.c
index 35db8e3e911..cd1508322c6 100644
--- a/server/atom.c
+++ b/server/atom.c
@@ -188,7 +188,7 @@ static void atom_table_dump( struct object *obj, int verbose )
         if (!entry) continue;
         fprintf( stderr, "  %04x: ref=%d pinned=%c hash=%d \"",
                  entry->atom, entry->count, entry->pinned ? 'Y' : 'N', entry->hash );
-        dump_strW( entry->str, entry->len / sizeof(WCHAR), stderr, "\"\"");
+        dump_strW( entry->str, entry->len, stderr, "\"\"");
         fprintf( stderr, "\"\n" );
     }
 }
diff --git a/server/object.c b/server/object.c
index aeb30684a8b..94a48c909bb 100644
--- a/server/object.c
+++ b/server/object.c
@@ -373,7 +373,7 @@ static void dump_name( struct object *obj )
     if (!name) return;
     if (name->parent) dump_name( name->parent );
     fputs( "\\\\", stderr );
-    dump_strW( name->name, name->len / sizeof(WCHAR), stderr, "[]" );
+    dump_strW( name->name, name->len, stderr, "[]" );
 }
 
 /* dump the name of an object to stderr */
diff --git a/server/registry.c b/server/registry.c
index 964e2ebd58f..bb65bb4818f 100644
--- a/server/registry.c
+++ b/server/registry.c
@@ -198,7 +198,7 @@ static void dump_path( const struct key *key, const struct key *base, FILE *f )
         dump_path( key->parent, base, f );
         fprintf( f, "\\\\" );
     }
-    dump_strW( key->name, key->namelen / sizeof(WCHAR), f, "[]" );
+    dump_strW( key->name, key->namelen, f, "[]" );
 }
 
 /* dump a value to a text file */
@@ -210,7 +210,7 @@ static void dump_value( const struct key_value *value, FILE *f )
     if (value->namelen)
     {
         fputc( '\"', f );
-        count = 1 + dump_strW( value->name, value->namelen / sizeof(WCHAR), f, "\"\"" );
+        count = 1 + dump_strW( value->name, value->namelen, f, "\"\"" );
         count += fprintf( f, "\"=" );
     }
     else count = fprintf( f, "@=" );
@@ -226,7 +226,7 @@ static void dump_value( const struct key_value *value, FILE *f )
         if (((WCHAR *)value->data)[value->len / sizeof(WCHAR) - 1]) break;
         if (value->type != REG_SZ) fprintf( f, "str(%x):", value->type );
         fputc( '\"', f );
-        dump_strW( (WCHAR *)value->data, value->len / sizeof(WCHAR), f, "\"\"" );
+        dump_strW( (WCHAR *)value->data, value->len, f, "\"\"" );
         fprintf( f, "\"\n" );
         return;
 
@@ -272,7 +272,7 @@ static void save_subkeys( const struct key *key, const struct key *base, FILE *f
         if (key->class)
         {
             fprintf( f, "#class=\"" );
-            dump_strW( key->class, key->classlen / sizeof(WCHAR), f, "\"\"" );
+            dump_strW( key->class, key->classlen, f, "\"\"" );
             fprintf( f, "\"\n" );
         }
         if (key->flags & KEY_SYMLINK) fputs( "#link\n", f );
diff --git a/server/symlink.c b/server/symlink.c
index bc75ee9a7eb..e5ee09f015a 100644
--- a/server/symlink.c
+++ b/server/symlink.c
@@ -81,7 +81,7 @@ static void symlink_dump( struct object *obj, int verbose )
     assert( obj->ops == &symlink_ops );
 
     fputs( "Symlink target=\"", stderr );
-    dump_strW( symlink->target, symlink->len / sizeof(WCHAR), stderr, "\"\"" );
+    dump_strW( symlink->target, symlink->len, stderr, "\"\"" );
     fputs( "\"\n", stderr );
 }
 
diff --git a/server/trace.c b/server/trace.c
index 95db31b4cb5..b60422c4481 100644
--- a/server/trace.c
+++ b/server/trace.c
@@ -105,7 +105,7 @@ static void dump_rectangle( const char *prefix, const rectangle_t *rect )
 static void dump_char_info( const char *prefix, const char_info_t *info )
 {
     fprintf( stderr, "%s{'", prefix );
-    dump_strW( &info->ch, 1, stderr, "\'\'" );
+    dump_strW( &info->ch, sizeof(info->ch), stderr, "\'\'" );
     fprintf( stderr, "',%04x}", info->attr );
 }
 
@@ -544,7 +544,7 @@ static void dump_varargs_string( const char *prefix, data_size_t size )
 static void dump_varargs_unicode_str( const char *prefix, data_size_t size )
 {
     fprintf( stderr, "%sL\"", prefix );
-    dump_strW( cur_data, size / sizeof(WCHAR), stderr, "\"\"" );
+    dump_strW( cur_data, size, stderr, "\"\"" );
     fputc( '\"', stderr );
     remove_data( size );
 }
@@ -824,9 +824,8 @@ static data_size_t dump_inline_unicode_string( const char *prefix, data_size_t p
     fputs( prefix, stderr );
     if (pos >= total_size) return pos;
     if (len > total_size - pos) len = total_size - pos;
-    len /= sizeof(WCHAR);
     dump_strW( (const WCHAR *)cur_data + pos/sizeof(WCHAR), len, stderr, "\"\"" );
-    return pos + len * sizeof(WCHAR);
+    return pos + (len / sizeof(WCHAR)) * sizeof(WCHAR);
 }
 
 static void dump_varargs_startup_info( const char *prefix, data_size_t size )
@@ -1133,7 +1132,7 @@ static void dump_varargs_object_attributes( const char *prefix, data_size_t size
         dump_inline_security_descriptor( ",sd=", (const struct security_descriptor *)(objattr + 1), objattr->sd_len );
         str = (const WCHAR *)objattr + (sizeof(*objattr) + objattr->sd_len) / sizeof(WCHAR);
         fprintf( stderr, ",name=L\"" );
-        dump_strW( str, objattr->name_len / sizeof(WCHAR), stderr, "\"\"" );
+        dump_strW( str, objattr->name_len, stderr, "\"\"" );
         fputc( '\"', stderr );
         remove_data( (sizeof(*objattr) + (objattr->sd_len & ~1) + (objattr->name_len & ~1) + 3) & ~3 );
     }
diff --git a/server/unicode.c b/server/unicode.c
index 3be1f55fe14..02233e22cf5 100644
--- a/server/unicode.c
+++ b/server/unicode.c
@@ -156,7 +156,7 @@ int dump_strW( const WCHAR *str, data_size_t len, FILE *f, const char escape[2]
     char *pos = buffer;
     int count = 0;
 
-    for (; len; str++, len--)
+    for (len /= sizeof(WCHAR); len; str++, len--)
     {
         if (pos > buffer + sizeof(buffer) - 8)
         {