diff --git a/Makefile.in b/Makefile.in
index 4172ae621..1885af7b3 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -1,4 +1,5 @@
-export NMAP_VERSION = 4.21ALPHA5
+# Extract the version string from nmap.h.
+export NMAP_VERSION := $(shell grep '^\#[ \t]*define[ \t]\+NMAP_VERSION' nmap.h | sed -e 's/.*"\(.*\)".*/\1/' -e 'q')
 NMAP_NAME= Nmap
 NMAP_URL= http://insecure.org
 NMAP_PLATFORM=@host@
@@ -22,7 +23,7 @@ DBGFLAGS =
 LIBPCAPDIR = @libpcapdir@
 LIBPCREDIR = @LIBPCREDIR@
 export LIBDNETDIR = @LIBDNETDIR@
-DEFS = @DEFS@ -DNMAP_VERSION=\"$(NMAP_VERSION)\" -DNMAP_NAME=\"$(NMAP_NAME)\" -DNMAP_URL=\"$(NMAP_URL)\" -DNMAP_PLATFORM=\"$(NMAP_PLATFORM)\" -DNMAPDATADIR=\"$(nmapdatadir)\"
+DEFS = @DEFS@ -DNMAP_NAME=\"$(NMAP_NAME)\" -DNMAP_URL=\"$(NMAP_URL)\" -DNMAP_PLATFORM=\"$(NMAP_PLATFORM)\" -DNMAPDATADIR=\"$(nmapdatadir)\"
 # For mtrace debugging -- see MTRACE define in main.cc for instructions
 # Should only be enabled during debugging and not in any real release.
 # DEFS += -DMTRACE=1
diff --git a/mswin32/Makefile b/mswin32/Makefile
index 834a15992..fedfcbacd 100644
--- a/mswin32/Makefile
+++ b/mswin32/Makefile
@@ -1,6 +1,6 @@
 MAKENSIS=/c/apps/NSIS/makensis.exe
 VCEXPRESS="/c/Program Files/Microsoft Visual Studio 8/Common7/IDE/VCExpress.exe"
-NMAP_VERSION:=$(shell grep "export NMAP_VERSION " ../Makefile.in | cut "-d " -f4)
+export NMAP_VERSION := $(shell grep '^\#[ \t]*define[ \t]\+NMAP_VERSION' ../nmap.h | sed -e 's/.*"\(.*\)".*/\1/' -e 'q')
 LOGLOC=c:nmapbuild.log
 
 winbuild:
diff --git a/nmap.h b/nmap.h
index cb5dc3d3f..9b6060456 100644
--- a/nmap.h
+++ b/nmap.h
@@ -250,6 +250,12 @@ void *realloc();
 
 /*******  DEFINES  ************/
 
+#ifndef NMAP_VERSION
+/* Edit this definition only within the quotes, because it is read from this
+   file by the makefiles. */
+#define NMAP_VERSION "4.21ALPHA5"
+#endif
+
 /* User configurable #defines: */
 #ifndef VERSION
 #define VERSION "1.60-Beta"
diff --git a/nmap_winconfig.h b/nmap_winconfig.h
index 85ef47cd7..e882bc15b 100644
--- a/nmap_winconfig.h
+++ b/nmap_winconfig.h
@@ -106,7 +106,6 @@
 /* Without this, Windows will give us all sorts of crap about using functions
    like strcpy() even if they are done safely */
 #define _CRT_SECURE_NO_DEPRECATE 1
-#define NMAP_VERSION "4.21ALPHA5"
 #define NMAP_NAME "Nmap"
 #define NMAP_URL "http://insecure.org"
 #define NMAP_PLATFORM "i686-pc-windows-windows"
diff --git a/nmapfe/nmapfe.c b/nmapfe/nmapfe.c
index 708ec9ca5..9cfad8c5d 100644
--- a/nmapfe/nmapfe.c
+++ b/nmapfe/nmapfe.c
@@ -428,6 +428,7 @@ GtkAdjustment *adjust;
 #ifdef WIN32
   opt.isr00t = 1;
   /* for nmap version */
+#include "nmap.h"
 #include "nmap_winconfig.h"
 #define VERSION NMAP_VERSION
 #else
diff --git a/nmapfe/nmapfe.h b/nmapfe/nmapfe.h
index 8cd46862f..f9136ffd1 100644
--- a/nmapfe/nmapfe.h
+++ b/nmapfe/nmapfe.h
@@ -109,8 +109,8 @@
  * Long live Aol and pr: Phreak. <grins>
  */
 
-#ifndef NMAP_H
-#define NMAP_H
+#ifndef NMAPFE_H
+#define NMAPFE_H
 
 #if MISSING_GTK
 #error "Your system does not appear to have GTK (www.gtk.org) installed.  Thus the Nmap X Front End will not compile.  You should still be able to use Nmap the normal way (via text console).  GUIs are for wimps anyway :)"
@@ -307,4 +307,4 @@ GtkWidget* create_main_win (void);
 GtkWidget* create_fileSelection(const char *title, char *filename, void (*action)(), GtkEntry *entry);
 GtkWidget* create_helpDialog(void);
 
-#endif /* NMAP_H */
+#endif /* NMAPFE_H */