diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index 5399d68901..e1feb8a0fa 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -1,3 +1,27 @@
+2000-03-27 23:20 GMT-5 David G. Holm <dholm@jsd-llc.com>
+   * include/hbapi.h
+   * include/hbapierr.h
+   * include/hbapifs.h
+   * include/hbapigt.h
+   * include/hbapiitm.h
+   * include/hbapilng.h
+   * include/hbapirdd.h
+   * include/hbcomp.h
+   * include/hbdate.h
+   * include/hberrors.h
+   * include/hbexprop.h
+   * include/hbinit.h
+   * include/hbmacro.h
+   * include/hbpp.h
+   * include/hbset.h
+   * include/hbsetup.h
+   * include/hbtrace.h
+   * include/hbvm.h
+   * include/hbvmpub.h
+     % Changed from using #if defined(__cplusplus) to using #if
+       defined(HB_EXTERN_C) and added definition of HB_EXTERN_C to
+       hbsetup.h #if defined(__cplusplus) && !defined(__IBMCPP__)
+
 20000328-03:35 GMT+1 Victor Szakats <info@szelvesz.hu>
 
    + doc/c_std.txt
diff --git a/harbour/include/hbapi.h b/harbour/include/hbapi.h
index 62b563c725..cd831f2dce 100644
--- a/harbour/include/hbapi.h
+++ b/harbour/include/hbapi.h
@@ -44,8 +44,8 @@
 #include "hbdefs.h"
 #include "hbvmpub.h"
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 /* items types and type checking macros */
@@ -484,8 +484,8 @@ extern char * hb_macroGetType( HB_ITEM_PTR );
 extern char * hb_version( USHORT uiMode );
 extern char * hb_valtypeGet( HB_ITEM_PTR );
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_APIEXT_H_ */
diff --git a/harbour/include/hbapierr.h b/harbour/include/hbapierr.h
index 951151f31d..1cdb20746e 100644
--- a/harbour/include/hbapierr.h
+++ b/harbour/include/hbapierr.h
@@ -39,8 +39,8 @@
 #include "hbapi.h"
 #include "error.ch"
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 /* Error codes (returned from hb_errLaunch()) */
@@ -155,8 +155,8 @@ typedef struct HB_ERROR_INFO_
 /*  set/get current error handler */
 extern HB_ERROR_INFO_PTR hb_errorHandler( HB_ERROR_INFO_PTR );
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_APIERR_H_ */
diff --git a/harbour/include/hbapifs.h b/harbour/include/hbapifs.h
index db1648fa22..3c169b11bc 100644
--- a/harbour/include/hbapifs.h
+++ b/harbour/include/hbapifs.h
@@ -57,8 +57,8 @@
 #include "hbapi.h"
 #include "fileio.ch"
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 #define FS_ERROR F_ERROR
@@ -131,8 +131,8 @@ typedef struct
 extern PHB_FNAME hb_fsFNameSplit( char * pszFileName ); /* Split given filename into path, name and extension */
 extern char *    hb_fsFNameMerge( char * pszFileName, PHB_FNAME pFileName ); /* This function joins path, name and extension into a string with a filename */
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_APIFS_H_ */
diff --git a/harbour/include/hbapigt.h b/harbour/include/hbapigt.h
index 7126727111..08c00e59cd 100644
--- a/harbour/include/hbapigt.h
+++ b/harbour/include/hbapigt.h
@@ -54,8 +54,8 @@
 #include "hbapi.h"
 #include "color.ch"
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 /* NOTE: The declaration of hb_gtSetPos(), hb_gtGetPos(), hb_gtWrite(), 
@@ -217,8 +217,8 @@ extern int    hb_mouse_CountButton( void );
 extern void   hb_mouse_SetBounds( int iTop, int iLeft, int iBottom, int iRight );
 extern void   hb_mouse_GetBounds( int * piTop, int * piLeft, int * piBottom, int * piRight );
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_APIGT_H_ */
diff --git a/harbour/include/hbapiitm.h b/harbour/include/hbapiitm.h
index 5f3e4874fc..15ea4ffb2e 100644
--- a/harbour/include/hbapiitm.h
+++ b/harbour/include/hbapiitm.h
@@ -38,8 +38,8 @@
 
 #include "hbapi.h"
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 #define HB_EVAL_PARAM_MAX_ 9
@@ -108,8 +108,8 @@ extern char *   hb_itemStr      ( PHB_ITEM pNumber, PHB_ITEM pWidth, PHB_ITEM pD
 extern char *   hb_itemString   ( PHB_ITEM pItem, ULONG * ulLen, BOOL * bFreeReq );  /* Convert any scalar to a string */
 extern PHB_ITEM hb_itemValToStr ( PHB_ITEM pItem ); /* Convert any scalar to a string */
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_APIITM_H_ */
diff --git a/harbour/include/hbapilng.h b/harbour/include/hbapilng.h
index 0cf33cbb93..84df8d565d 100644
--- a/harbour/include/hbapilng.h
+++ b/harbour/include/hbapilng.h
@@ -36,8 +36,8 @@
 #ifndef HB_APILNG_H_
 #define HB_APILNG_H_
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 #define HB_LANG_TEXT_DATEFMT    0
@@ -107,8 +107,8 @@ extern char *   hb_langDGetErrorIntr	( ULONG ulIndex );
 extern PHB_LANG hb_langNew              ( void );
 extern void     hb_langDelete           ( PHB_LANG lang );
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_APILNG_H_ */
diff --git a/harbour/include/hbapirdd.h b/harbour/include/hbapirdd.h
index df9afd5c9f..13fd28bfbb 100644
--- a/harbour/include/hbapirdd.h
+++ b/harbour/include/hbapirdd.h
@@ -39,8 +39,8 @@
 #include "hbapi.h"
 #include "hbapifs.h"
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 /* RDD virtual machine integration functions */
@@ -1102,8 +1102,8 @@ extern ERRCODE hb_rddDisinherit( BYTE * drvName );
 extern USHORT  hb_rddExtendType( USHORT fieldType );
 extern USHORT  hb_rddFieldType( USHORT extendType );
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_APIRDD_H_ */
diff --git a/harbour/include/hbcomp.h b/harbour/include/hbcomp.h
index ada203af52..e146ff1786 100644
--- a/harbour/include/hbcomp.h
+++ b/harbour/include/hbcomp.h
@@ -49,8 +49,8 @@
 #include "hbexprop.h"
 #include "hbpcode.h"
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 /* compiler related declarations */
@@ -371,8 +371,8 @@ extern char *      hb_comp_szWarnings[];
 #define HB_EXITLEVEL_SETEXIT    1
 #define HB_EXITLEVEL_DELTARGET  2
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_COMP_H_ */
diff --git a/harbour/include/hbdate.h b/harbour/include/hbdate.h
index 9689f8f552..e62df4fc14 100644
--- a/harbour/include/hbdate.h
+++ b/harbour/include/hbdate.h
@@ -36,8 +36,8 @@
 #ifndef HB_DATE_H_
 #define HB_DATE_H_
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 /* In msgxxx.c modules */
@@ -56,8 +56,8 @@ extern void     hb_dateStrGet( const char * szDate, long * plDay, long * plMonth
 extern char *   hb_dateDecStr( char * szDate, long lJulian );
 extern long     hb_dateEncStr( char * szDate );
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_DATE_H_ */
diff --git a/harbour/include/hberrors.h b/harbour/include/hberrors.h
index bdebb5e7d8..99ca4b3de7 100644
--- a/harbour/include/hberrors.h
+++ b/harbour/include/hberrors.h
@@ -36,8 +36,8 @@
 #ifndef HB_ERRORS_H_
 #define HB_ERRORS_H_
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 /*
@@ -130,8 +130,8 @@
 extern void hb_compGenError( char * _szErrors[], char cPrefix, int iError, char * szError1, char * szError2 ); /* generic parsing error management function */
 extern void hb_compGenWarning( char * _szWarnings[], char cPrefix, int iWarning, char * szWarning1, char * szWarning2); /* generic parsing warning management function */
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_ERRORS_H_ */
diff --git a/harbour/include/hbexprop.h b/harbour/include/hbexprop.h
index 6b67a9cdc6..ab011d23f2 100644
--- a/harbour/include/hbexprop.h
+++ b/harbour/include/hbexprop.h
@@ -38,8 +38,8 @@
 
 #include "hbapi.h"
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 /* value types seen at language level
@@ -351,8 +351,8 @@ void hb_compExprDelete( HB_EXPR_PTR );
 
 #endif
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif  /* HB_EXPROP_H_ */
diff --git a/harbour/include/hbinit.h b/harbour/include/hbinit.h
index c3b54eb8cd..b866eaa852 100644
--- a/harbour/include/hbinit.h
+++ b/harbour/include/hbinit.h
@@ -36,8 +36,8 @@
 #ifndef HB_INIT_H_
 #define HB_INIT_H_
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 extern void hb_vmProcessSymbols( PHB_SYMB pSymbols, USHORT uiSymbols ); /* statics symbols initialization */
@@ -132,8 +132,8 @@ extern void hb_vmProcessSymbols( PHB_SYMB pSymbols, USHORT uiSymbols ); /* stati
 
 #endif /* HARBOUR_STRICT_ANSI_C */
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_INIT_H_ */
diff --git a/harbour/include/hbmacro.h b/harbour/include/hbmacro.h
index 87b2ce11eb..9f3c8c6f23 100644
--- a/harbour/include/hbmacro.h
+++ b/harbour/include/hbmacro.h
@@ -55,8 +55,8 @@
 #include "hbexprop.h"
 #include "hbpcode.h"
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 /* flags for compilation process
@@ -135,8 +135,8 @@ extern void hb_compGenPCodeN( BYTE * pBuffer, ULONG ulSize, HB_MACRO_DECL );
 extern void hb_compCodeBlockStart( HB_MACRO_DECL );
 extern void hb_compCodeBlockEnd( HB_MACRO_DECL );
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_MACRO_H_ */
diff --git a/harbour/include/hbpp.h b/harbour/include/hbpp.h
index 074ca5a255..e5a166348a 100644
--- a/harbour/include/hbpp.h
+++ b/harbour/include/hbpp.h
@@ -41,8 +41,8 @@
 #include "hberrors.h"
 #include "hbver.h"
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 /* the list of pathnames to search with #include */
@@ -107,8 +107,8 @@ extern DEFINES *  hb_pp_topDefine;
 extern COMMANDS * hb_pp_topCommand;
 extern COMMANDS * hb_pp_topTranslate;
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_PP_H_ */
diff --git a/harbour/include/hbset.h b/harbour/include/hbset.h
index 0eabe6778f..712b9126d7 100644
--- a/harbour/include/hbset.h
+++ b/harbour/include/hbset.h
@@ -86,8 +86,8 @@
 #include "hbapifs.h"
 #include "hbapigt.h"
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 typedef enum
@@ -211,8 +211,8 @@ extern HB_SET_STRUCT hb_set;
 extern void hb_setInitialize( void );
 extern void hb_setRelease( void );
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_SET_H_ */
diff --git a/harbour/include/hbsetup.h b/harbour/include/hbsetup.h
index 5c8e874984..06871a242f 100644
--- a/harbour/include/hbsetup.h
+++ b/harbour/include/hbsetup.h
@@ -232,5 +232,12 @@
    #endif
 #endif
 
-#endif /* HB_SETUP_H_ */
+/* ***********************************************************************
+ * Extern "C" detection
+ */
 
+#if defined(__cplusplus) && !defined(__IBMCPP__)
+   #define HB_EXTERN_C
+#endif
+
+#endif /* HB_SETUP_H_ */
diff --git a/harbour/include/hbtrace.h b/harbour/include/hbtrace.h
index 235e75cc06..f0f8132d28 100644
--- a/harbour/include/hbtrace.h
+++ b/harbour/include/hbtrace.h
@@ -36,8 +36,8 @@
 #ifndef HB_TRACE_H_
 #define HB_TRACE_H_
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 /*
@@ -185,8 +185,8 @@ extern int    hb_tracelevel( int new_level );
 extern int    hb_tr_level( void );
 extern void   hb_tr_trace( char * fmt, ... );
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_TRACE_H_ */
diff --git a/harbour/include/hbvm.h b/harbour/include/hbvm.h
index 9c8e258ea0..bd258193b7 100644
--- a/harbour/include/hbvm.h
+++ b/harbour/include/hbvm.h
@@ -38,8 +38,8 @@
 
 #include "hbapi.h"
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 /* Harbour virtual machine init/exit functions */
@@ -89,8 +89,8 @@ extern void    hb_vmPushSymbol( PHB_SYMB pSym ); /* pushes a function pointer on
 extern void    hb_stackDispCall( void );
 extern void    hb_stackPop( void );        /* pops an item from the stack */
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_VM_H_ */
diff --git a/harbour/include/hbvmpub.h b/harbour/include/hbvmpub.h
index 3dd8f7fcb8..dbb310c178 100644
--- a/harbour/include/hbvmpub.h
+++ b/harbour/include/hbvmpub.h
@@ -38,8 +38,8 @@
 
 #include "hbdefs.h"
 
-#if defined(__cplusplus)
-//extern "C" {
+#if defined(HB_EXTERN_C)
+extern "C" {
 #endif
 
 struct _HB_DYNS;
@@ -76,8 +76,8 @@ typedef HB_DYNS_FUNC( PHB_DYNS_FUNC );
 
 extern void hb_vmExecute( BYTE * pCode, PHB_SYMB pSymbols );  /* invokes the virtual machine */
 
-#if defined(__cplusplus)
-//}
+#if defined(HB_EXTERN_C)
+}
 #endif
 
 #endif /* HB_VMPUB_H_ */