diff --git a/ProcessUNIX.c b/ProcessUNIX.c
index 19922111aa836448ff50fc8ade1e1715f5884e47..83838affcdf73eff36fce7f43258b6d4dc122263 100644
--- a/ProcessUNIX.c
+++ b/ProcessUNIX.c
@@ -63,10 +63,6 @@ do.
 #include <dirent.h>    /* DIR, dirent */
 #include <ctype.h>     /* isspace */
 
-#ifdef __HAIKU__
-#undef __BEOS__
-#endif
-
 #if defined(__VMS)
 # define KWSYSPE_VMS_NONBLOCK , O_NONBLOCK
 #else
diff --git a/SystemTools.cxx b/SystemTools.cxx
index 99256406478757a2ef44297745431a2d6e21ad10..b8fa2dfa87ab5a7df8962bb12f4ca1e475702453 100644
--- a/SystemTools.cxx
+++ b/SystemTools.cxx
@@ -157,7 +157,7 @@ public:
 #include <os/storage/Path.h>
 #endif
 
-#if defined(__BEOS__) && !defined(__ZETA__) && !defined(__HAIKU__)
+#if defined(__BEOS__) && !defined(__ZETA__)
 #include <be/kernel/OS.h>
 #include <be/storage/Path.h>
 
diff --git a/testDynamicLoader.cxx b/testDynamicLoader.cxx
index a7adbcad9fcd2ea664cf41485215849a176f589b..cbfb65b1c1043d28454b2c939aee9530235056d0 100644
--- a/testDynamicLoader.cxx
+++ b/testDynamicLoader.cxx
@@ -15,7 +15,7 @@
 #include KWSYS_HEADER(ios/iostream)
 #include KWSYS_HEADER(stl/string)
 
-#if defined(__BEOS__) && !defined(__HAIKU__)
+#if defined(__BEOS__)
 #include <be/kernel/OS.h>  /* disable_debugger() API. */
 #endif
 
diff --git a/testProcess.c b/testProcess.c
index ec561ead7cef3ccce24b4e0fb975323013d8b0c6..269b84ba8f69f8266fd17a956895dac77dab950e 100644
--- a/testProcess.c
+++ b/testProcess.c
@@ -32,7 +32,7 @@
 # pragma warn -8060 /* possibly incorrect assignment */
 #endif
 
-#if defined(__BEOS__) && !defined(__ZETA__) && !defined(__HAIKU__)
+#if defined(__BEOS__) && !defined(__ZETA__)
 /* BeOS 5 doesn't have usleep(), but it has snooze(), which is identical. */
 # include <be/kernel/OS.h>
 static inline void testProcess_usleep(unsigned int msec)