diff --git a/programs/reg/tests/add.c b/programs/reg/tests/add.c
index 36fa634796d..469f354de39 100644
--- a/programs/reg/tests/add.c
+++ b/programs/reg/tests/add.c
@@ -154,7 +154,7 @@ void delete_key_(const char *file, unsigned line, HKEY root, const char *path, R
     }
 }
 
-LONG delete_tree(HKEY root, const char *path, REGSAM sam)
+LONG delete_tree_(const char *file, unsigned line, HKEY root, const char *path, REGSAM sam)
 {
     HKEY hkey;
     LONG ret;
@@ -163,6 +163,7 @@ LONG delete_tree(HKEY root, const char *path, REGSAM sam)
     static const char empty[1];
 
     ret = RegOpenKeyExA(root, path, 0, KEY_READ|sam, &hkey);
+    lok(!ret || ret == ERROR_FILE_NOT_FOUND, "RegOpenKeyExA failed, got error %d\n", ret);
     if (ret) return ret;
 
     ret = RegQueryInfoKeyA(hkey, NULL, NULL, NULL, NULL, &max_subkey_len,
@@ -184,7 +185,7 @@ LONG delete_tree(HKEY root, const char *path, REGSAM sam)
         ret = RegEnumKeyExA(hkey, 0, subkey_name, &subkey_len, NULL, NULL, NULL, NULL);
         if (ret == ERROR_NO_MORE_ITEMS) break;
         if (ret) goto cleanup;
-        ret = delete_tree(hkey, subkey_name, sam);
+        ret = delete_tree_(file, line, hkey, subkey_name, sam);
         if (ret) goto cleanup;
     }
 
@@ -193,6 +194,8 @@ LONG delete_tree(HKEY root, const char *path, REGSAM sam)
     else
         ret = RegDeleteKeyExA(hkey, empty, sam, 0);
 
+    lok(!ret, "Failed to delete registry key, got error %d\n", ret);
+
 cleanup:
     HeapFree(GetProcessHeap(), 0, subkey_name);
     RegCloseKey(hkey);
diff --git a/programs/reg/tests/reg_test.h b/programs/reg/tests/reg_test.h
index a5d7169beb4..3f64e552a19 100644
--- a/programs/reg/tests/reg_test.h
+++ b/programs/reg/tests/reg_test.h
@@ -64,7 +64,8 @@ void add_key_(const char *file, unsigned line, const HKEY root, const char *path
 #define delete_key(r,p,s) delete_key_(__FILE__,__LINE__,r,p,s)
 void delete_key_(const char *file, unsigned line, HKEY root, const char *path, REGSAM sam);
 
-LONG delete_tree(HKEY root, const char *path, REGSAM sam);
+#define delete_tree(r,p,s) delete_tree_(__FILE__,__LINE__,r,p,s)
+LONG delete_tree_(const char *file, unsigned line, HKEY root, const char *path, REGSAM sam);
 
 #define add_value(k,n,t,d,s) add_value_(__FILE__,__LINE__,k,n,t,d,s)
 void add_value_(const char *file, unsigned line, HKEY hkey, const char *name,