diff --git a/reactos/drivers/filesystems/reiserfs/CMakeLists.txt b/reactos/drivers/filesystems/reiserfs/CMakeLists.txt
index 4ec66cfea7a..16dfc89e33e 100644
--- a/reactos/drivers/filesystems/reiserfs/CMakeLists.txt
+++ b/reactos/drivers/filesystems/reiserfs/CMakeLists.txt
@@ -81,7 +81,7 @@ add_library(reiserfs SHARED ${SOURCE} src/rfsd.rc)
 if(NOT MSVC)
     add_target_compile_flags(reiserfs "-Wno-pointer-sign -Wno-unused-function")
     if(NOT CMAKE_C_COMPILER_ID STREQUAL "Clang")
-        add_target_compile_flags(reiserfs "-Wno-unused-but-set-variable -Wno-unused-variable -Wno-missing-braces")
+        add_target_compile_flags(reiserfs "-Wno-unused-but-set-variable -Wno-unused-variable -Wno-missing-braces -D__GCC__")
     endif()
 else()
     #disable warnings: "unreferenced local variable", "initialized, but not used variable", "benign include"
diff --git a/reactos/drivers/filesystems/reiserfs/inc/linux/reiserfs_fs.h b/reactos/drivers/filesystems/reiserfs/inc/linux/reiserfs_fs.h
index dd5bd1617e6..0c59d3eb32c 100644
--- a/reactos/drivers/filesystems/reiserfs/inc/linux/reiserfs_fs.h
+++ b/reactos/drivers/filesystems/reiserfs/inc/linux/reiserfs_fs.h
@@ -3,7 +3,11 @@
  */
 
 #ifdef __GCC__
+#ifndef __REACTOS__
  #define __PACKED		__PACKED
+#else
+ #define __PACKED		__attribute__((packed))
+#endif
 #else
  #define __PACKED		
 #endif
diff --git a/reactos/drivers/filesystems/reiserfs/inc/reiserfs.h b/reactos/drivers/filesystems/reiserfs/inc/reiserfs.h
index cc84dbb79c6..85a1a782292 100644
--- a/reactos/drivers/filesystems/reiserfs/inc/reiserfs.h
+++ b/reactos/drivers/filesystems/reiserfs/inc/reiserfs.h
@@ -4,7 +4,11 @@
 #include <linux/types.h>
 
 #ifdef __GCC__
+#ifndef __REACTOS__
  #define __PACKED		__PACKED
+#else
+ #define __PACKED		__attribute__((packed))
+#endif
 #else
  #define __PACKED		
 #endif