diff --git a/reactos/include/host/typedefs.h b/reactos/include/host/typedefs.h
index 49de4f3235d..2b60d3de798 100644
--- a/reactos/include/host/typedefs.h
+++ b/reactos/include/host/typedefs.h
@@ -29,7 +29,7 @@
 /* Basic definitions */
 #define UNIMPLEMENTED { printf("%s unimplemented\n", __FUNCTION__); exit(1); }
 #define ASSERT(x) assert(x)
-#define ASSERTMSG(x, m) assert(x)
+#define ASSERTMSG(m, x) assert(x)
 #define DPRINT if (0) printf
 #define DPRINT1 printf
 
diff --git a/reactos/include/reactos/debug.h b/reactos/include/reactos/debug.h
index f6b38d37d5a..f467dc8377c 100644
--- a/reactos/include/reactos/debug.h
+++ b/reactos/include/reactos/debug.h
@@ -79,9 +79,9 @@ RtlAssert(
 
 #ifndef ASSERTMSG
 #ifndef NASSERT
-#define ASSERTMSG(x,m) if (!(x)) { RtlAssert((PVOID)#x, __FILE__, __LINE__, m); }
+#define ASSERTMSG(m, x) if (!(x)) { RtlAssert((PVOID)#x, __FILE__, __LINE__, m); }
 #else
-#define ASSERTMSG(x)
+#define ASSERTMSG(m, x)
 #endif
 #endif