diff --git a/source/blender/makesdna/intern/dna_genfile.c b/source/blender/makesdna/intern/dna_genfile.c
index 6322cb459dd..b0a1ef2d41f 100644
--- a/source/blender/makesdna/intern/dna_genfile.c
+++ b/source/blender/makesdna/intern/dna_genfile.c
@@ -726,21 +726,21 @@ static void cast_primitive_type(const eSDNA_Type old_type,
                                 const eSDNA_Type new_type,
                                 const int array_len,
                                 const char *old_data,
                                 char *new_data)
 {
   /* define lengths */
   const int oldlen = DNA_elem_type_size(old_type);
   const int curlen = DNA_elem_type_size(new_type);

   double old_value_f = 0.0;
-  uint64_t old_value_i = 0;
+  int64_t old_value_i = 0;

   for (int a = 0; a < array_len; a++) {
     switch (old_type) {
       case SDNA_TYPE_CHAR:
         old_value_i = *old_data;
         old_value_f = (double)old_value_i;
         break;
       case SDNA_TYPE_UCHAR:
         old_value_i = *((unsigned char *)old_data);
         old_value_f = (double)old_value_i;