diff --git a/src/os_unix.c b/src/os_unix.c
index a0189ea..9a48804 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -5666,7 +5666,7 @@
 		{
 		    typval_T *item = &dict_lookup(hi)->di_tv;
 
-		    vim_setenv((char_u*)hi->hi_key, tv_get_string(item));
+		    vim_setenv(hi->hi_key, tv_get_string(item));
 		    --todo;
 		}
 	}
@@ -7487,7 +7487,7 @@
     if (hinstLib == NULL)
     {
 	// "dlerr" must be used before dlclose()
-	dlerr = (char *)dlerror();
+	dlerr = dlerror();
 	if (dlerr != NULL)
 	    semsg(_("dlerror = \"%s\""), dlerr);
     }
@@ -7522,7 +7522,7 @@
 	    {
 # if defined(USE_DLOPEN)
 		*(void **)(&ProcAdd) = dlsym(hinstLib, (const char *)funcname);
-		dlerr = (char *)dlerror();
+		dlerr = dlerror();
 # else
 		if (shl_findsym(&hinstLib, (const char *)funcname,
 					TYPE_PROCEDURE, (void *)&ProcAdd) < 0)
@@ -7544,7 +7544,7 @@
 	    {
 # if defined(USE_DLOPEN)
 		*(void **)(&ProcAddI) = dlsym(hinstLib, (const char *)funcname);
-		dlerr = (char *)dlerror();
+		dlerr = dlerror();
 # else
 		if (shl_findsym(&hinstLib, (const char *)funcname,
 				       TYPE_PROCEDURE, (void *)&ProcAddI) < 0)