diff --git a/drivers/filesystems/udfs/Include/Sys_spec_lib.cpp b/drivers/filesystems/udfs/Include/Sys_spec_lib.cpp
index d2602d6f76b..d775e86bd2d 100644
--- a/drivers/filesystems/udfs/Include/Sys_spec_lib.cpp
+++ b/drivers/filesystems/udfs/Include/Sys_spec_lib.cpp
@@ -806,7 +806,7 @@ MyAppendUnicodeToString_(
   #define UDF_UNC_STR_TAG "AppStr"
 #endif 
 
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 
     __asm push  ebx
     __asm push  esi
@@ -868,7 +868,7 @@ MyInitUnicodeString(
 
     USHORT i;
 
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 
     __asm push  ebx
     __asm push  esi
diff --git a/drivers/filesystems/udfs/Include/wcache_lib.cpp b/drivers/filesystems/udfs/Include/wcache_lib.cpp
index db479131132..b00dc50357d 100644
--- a/drivers/filesystems/udfs/Include/wcache_lib.cpp
+++ b/drivers/filesystems/udfs/Include/wcache_lib.cpp
@@ -455,7 +455,7 @@ WCacheGetSortedListIndex(
     if(!BlockCount)
         return 0;
 
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 
     __asm push  ecx
     __asm push  ebx
diff --git a/drivers/filesystems/udfs/namesup.cpp b/drivers/filesystems/udfs/namesup.cpp
index a028f283f87..b30ad8bc2aa 100644
--- a/drivers/filesystems/udfs/namesup.cpp
+++ b/drivers/filesystems/udfs/namesup.cpp
@@ -24,7 +24,7 @@ UDFDissectName(
 
     USHORT  i;
 
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 
     PWCHAR retval;
 
diff --git a/drivers/filesystems/udfs/udf_info/alloc.cpp b/drivers/filesystems/udfs/udf_info/alloc.cpp
index 0d55dcfb4bb..49905fb61a6 100644
--- a/drivers/filesystems/udfs/udf_info/alloc.cpp
+++ b/drivers/filesystems/udfs/udf_info/alloc.cpp
@@ -50,7 +50,7 @@ UDFPhysLbaToPart(
     )
 {
     PUDFPartMap pm = Vcb->Partitions;
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined (_X86_) && defined (_MSC_VER) && !defined(__clang__)
     uint32 retval;
     __asm {
         push ebx
@@ -1280,7 +1280,7 @@ UDFSetBits__(
     IN uint32 bc
     )
 {
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(__clang__)
     __asm {
         push eax
         push ebx
@@ -1388,7 +1388,7 @@ UDFClrBits__(
     IN uint32 bc
     )
 {
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(__clang__)
     __asm {
         push eax
         push ebx
diff --git a/drivers/filesystems/udfs/udf_info/dirtree.cpp b/drivers/filesystems/udfs/udf_info/dirtree.cpp
index 0f425c7032d..d20e3539669 100644
--- a/drivers/filesystems/udfs/udf_info/dirtree.cpp
+++ b/drivers/filesystems/udfs/udf_info/dirtree.cpp
@@ -242,7 +242,7 @@ UDFDirIndexTrunc(
 /*
     This routine returns pointer to DirIndex item with index i.
  */
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(__clang__)
 __declspec (naked)
 #endif
 PDIR_INDEX_ITEM
@@ -252,7 +252,7 @@ UDFDirIndex(
     IN uint32 i                // EDX
     )
 {
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(__clang__)
     __asm {
         push ebx
         push ecx
diff --git a/drivers/filesystems/udfs/udf_info/extent.cpp b/drivers/filesystems/udfs/udf_info/extent.cpp
index 8c76c2b0188..f949cf1d52a 100644
--- a/drivers/filesystems/udfs/udf_info/extent.cpp
+++ b/drivers/filesystems/udfs/udf_info/extent.cpp
@@ -146,7 +146,7 @@ UDFGetExtentLength(
     if(!Extent) return 0;
     int64 i=0;
 
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 
     __asm push  ebx
     __asm push  ecx
@@ -227,7 +227,7 @@ UDFGetMappingLength(
     if(!Extent) return 0;
     uint32 i=0;
 
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
     __asm push  ebx
 
     __asm mov   ebx,Extent
diff --git a/drivers/filesystems/udfs/udf_info/mount.cpp b/drivers/filesystems/udfs/udf_info/mount.cpp
index 7ce68faa9fe..2cbaccc5064 100644
--- a/drivers/filesystems/udfs/udf_info/mount.cpp
+++ b/drivers/filesystems/udfs/udf_info/mount.cpp
@@ -2939,7 +2939,7 @@ UDFCheckZeroBuf(
     )
 {
 
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 
     BOOLEAN RC = FALSE;
 
diff --git a/drivers/filesystems/udfs/udf_info/udf_info.cpp b/drivers/filesystems/udfs/udf_info/udf_info.cpp
index 0d9e5c1bcd5..6f29d88e5f1 100644
--- a/drivers/filesystems/udfs/udf_info/udf_info.cpp
+++ b/drivers/filesystems/udfs/udf_info/udf_info.cpp
@@ -4280,7 +4280,7 @@ UDFCompareFileInfo(
 #pragma warning(disable:4035)               // re-enable below
 #endif
 
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 __declspec (naked)
 #endif // _X86_
 uint32 
@@ -4290,7 +4290,7 @@ crc32(
     IN uint32 len // EDX
     )
 {
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 //    uint32 _Size = len;
 
     __asm {
@@ -4346,7 +4346,7 @@ EO_CRC:
     The polynomial used is: x^16 + x^12 + x^15 + 1
 */
 
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 __declspec (naked)
 #endif // _X86_
 uint16 
@@ -4356,7 +4356,7 @@ UDFUnicodeCksum(
     uint32 n  // EDX
     )
 {
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 //    uint32 _Size = n;
 
     __asm {
@@ -4412,7 +4412,7 @@ EO_uCRC:
 #endif // _X86_
 } // end UDFUnicodeCksum()
 
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 __declspec (naked)
 #endif // _X86_
 uint16 
@@ -4422,7 +4422,7 @@ UDFUnicodeCksum150(
     uint32 n  // EDX
     )
 {
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 //    uint32 _Size = n;
 
     __asm {
@@ -4517,7 +4517,7 @@ use16_2:
     The OSTA-UDF(tm) 1.50 standard states that using CRCs is mandatory.
     The polynomial used is: x^16 + x^12 + x^15 + 1
 */
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 __declspec (naked)
 #endif // _X86_
 uint16 
@@ -4527,7 +4527,7 @@ UDFCrc(
     IN uint32 Size  // EDX
     )
 {
-#if defined (_X86_) && defined (_MSC_VER)
+#if defined(_X86_) && defined(_MSC_VER) && !defined(__clang__)
 //    uint32 _Size = Size;
 
     __asm {
diff --git a/drivers/filesystems/udfs/write.cpp b/drivers/filesystems/udfs/write.cpp
index 467e41b6beb..ceaa69bda01 100644
--- a/drivers/filesystems/udfs/write.cpp
+++ b/drivers/filesystems/udfs/write.cpp
@@ -324,7 +324,7 @@ UDFCommonWrite(
                 // flush system cache
                 UDFFlushLogicalVolume(NULL, NULL, Vcb, 0);
             }
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(__clang__)
 /* FIXME */
             if(PagingIo) {
                 CollectStatistics(Vcb, MetaDataWrites);
@@ -444,7 +444,7 @@ UDFCommonWrite(
             TruncatedLength = WriteLength;
         }
 
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(__clang__)
 /* FIXME */
         if(PagingIo) {
             CollectStatistics(Vcb, UserFileWrites);
@@ -906,7 +906,7 @@ UDFCommonWrite(
 
             UDFUnlockCallersBuffer(PtrIrpContext, Irp, SystemBuffer);
 
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(__clang__)
 /* FIXME */
             if(PagingIo) {
                 CollectStatistics(Vcb, UserDiskWrites);