diff --git a/src/ctrl/ctrl_core.c b/src/ctrl/ctrl_core.c
index 8c8fa31b..47c3ab35 100644
--- a/src/ctrl/ctrl_core.c
+++ b/src/ctrl/ctrl_core.c
@@ -857,6 +857,7 @@ ctrl_init(void)
     String8 user_data_folder = push_str8f(scratch.arena, "%S/raddbg/logs", user_program_data_path);
     os_make_directory(user_data_folder);
     ctrl_state->ctrl_thread_log_path = push_str8f(ctrl_state->arena, "%S/ctrl_thread.raddbg_log", user_data_folder);
+    os_write_data_to_file_path(ctrl_state->ctrl_thread_log_path, str8_zero());
     scratch_end(scratch);
   }
   ctrl_state->ctrl_thread_entity_store = ctrl_entity_store_alloc();
diff --git a/src/os/core/os_core.c b/src/os/core/os_core.c
index 5f4fc32d..830fc677 100644
--- a/src/os/core/os_core.c
+++ b/src/os/core/os_core.c
@@ -117,7 +117,7 @@ internal B32
 os_append_data_to_file_path(String8 path, String8 data)
 {
   B32 good = 0;
-  OS_Handle file = os_file_open(OS_AccessFlag_Write, path);
+  OS_Handle file = os_file_open(OS_AccessFlag_Write|OS_AccessFlag_Append, path);
   if(!os_handle_match(file, os_handle_zero()))
   {
     good = 1;
diff --git a/src/os/core/os_core.h b/src/os/core/os_core.h
index c31d2a61..ea8863da 100644
--- a/src/os/core/os_core.h
+++ b/src/os/core/os_core.h
@@ -13,8 +13,9 @@ enum
   OS_AccessFlag_Read       = (1<<0),
   OS_AccessFlag_Write      = (1<<1),
   OS_AccessFlag_Execute    = (1<<2),
-  OS_AccessFlag_ShareRead  = (1<<3),
-  OS_AccessFlag_ShareWrite = (1<<4),
+  OS_AccessFlag_Append     = (1<<3),
+  OS_AccessFlag_ShareRead  = (1<<4),
+  OS_AccessFlag_ShareWrite = (1<<5),
 };
 
 ////////////////////////////////
diff --git a/src/os/core/win32/os_core_win32.c b/src/os/core/win32/os_core_win32.c
index 0d13d0e4..b131287f 100644
--- a/src/os/core/win32/os_core_win32.c
+++ b/src/os/core/win32/os_core_win32.c
@@ -664,6 +664,7 @@ os_file_open(OS_AccessFlags flags, String8 path)
   if(flags & OS_AccessFlag_ShareRead)  {share_mode |= FILE_SHARE_READ;}
   if(flags & OS_AccessFlag_ShareWrite) {share_mode |= FILE_SHARE_WRITE|FILE_SHARE_DELETE;}
   if(flags & OS_AccessFlag_Write)   {creation_disposition = CREATE_ALWAYS;}
+  if(flags & OS_AccessFlag_Append)  {creation_disposition = OPEN_ALWAYS;}
   HANDLE file = CreateFileW((WCHAR *)path16.str, access_flags, share_mode, 0, creation_disposition, FILE_ATTRIBUTE_NORMAL, 0);
   if(file != INVALID_HANDLE_VALUE)
   {