diff --git a/reactos/include/psdk/intrin_x86.h b/reactos/include/psdk/intrin_x86.h
index 26ca223e3d6..6aa7be4f22e 100644
--- a/reactos/include/psdk/intrin_x86.h
+++ b/reactos/include/psdk/intrin_x86.h
@@ -680,6 +680,15 @@ static __inline__ __attribute__((always_inline)) unsigned short _rotl16(const un
 	return retval;
 }
 
+#ifndef __MSVCRT__
+static __inline__ __attribute__((always_inline)) unsigned short _rotl(const unsigned long value, const unsigned char shift)
+{
+	unsigned short retval;
+	__asm__("roll %b[shift], %w[retval]" : [retval] "=rm" (retval) : "[retval]" (value), [shift] "Nc" (shift));
+	return retval;
+}
+#endif
+
 static __inline__ __attribute__((always_inline)) unsigned char _rotr8(const unsigned char value, const unsigned char shift)
 {
 	unsigned char retval;
diff --git a/reactos/lib/rtl/rtl.h b/reactos/lib/rtl/rtl.h
index a557d834621..7f1eaf73ad7 100644
--- a/reactos/lib/rtl/rtl.h
+++ b/reactos/lib/rtl/rtl.h
@@ -14,6 +14,7 @@
 /* We're a core NT DLL, we don't import syscalls */
 #define WIN32_NO_STATUS
 #define _INC_SWPRINTF_INL_
+#undef __MSVCRT__
 
 /* C Headers */
 #include <stdlib.h>
diff --git a/reactos/ntoskrnl/include/ntoskrnl.h b/reactos/ntoskrnl/include/ntoskrnl.h
index 775f99300eb..de9c03c85ff 100644
--- a/reactos/ntoskrnl/include/ntoskrnl.h
+++ b/reactos/ntoskrnl/include/ntoskrnl.h
@@ -9,6 +9,7 @@
 /* INCLUDES ******************************************************************/
 
 /* Version Data */
+#undef __MSVCRT__
 #include <psdk/ntverp.h>
 #define _WIN32_WINNT _WIN32_WINNT_WS03
 #define NTDDI_VERSION NTDDI_WS03SP1