diff --git a/include/gtkwave/fstapi.c b/include/gtkwave/fstapi.c
index 016511844..280721b0e 100644
--- a/include/gtkwave/fstapi.c
+++ b/include/gtkwave/fstapi.c
@@ -295,7 +295,7 @@ return(realpath(path, resolved_path));
 #ifdef __MINGW32__
 if(!resolved_path)
         {
-        resolved_path = (unsigned char *)malloc(PATH_MAX+1);
+        resolved_path = (char *)malloc(PATH_MAX+1);
         }
 return(_fullpath(resolved_path, path, PATH_MAX));
 #else
@@ -2164,7 +2164,7 @@ if(xc && !xc->already_in_close && !xc->already_in_flush)
 #ifdef __MINGW32__
         {
         int flen = strlen(xc->filename);
-        char *hf = calloc(1, flen + 6);
+        char *hf = (char*)calloc(1, flen + 6);
         strcpy(hf, xc->filename);
 
         if(xc->compress_hier)