diff --git a/CHANGELOG b/CHANGELOG
index 975fb7ec5..b916bb052 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,12 @@
 # Nmap Changelog ($Id$); -*-text-*-
 
+o Fixed a bug which caused Nmap to send bad checksums on Solaris 10
+  x86.  This was due to a workaround for an Ancient Solaris 2.1 bug
+  which activated when the OS string matched "solaris2.1*".  The
+  problem has now been resolved until Solaris 20 comes out and hits
+  our "solaris2.2*" bug workarounds. Thanks to Nathan Bills for the
+  problem report.  Fixed by Fyodor.
+
 o We now compile in IPv6 support on Windows.  In order to use this,
   you need to have IPv6 set up.  It is installed by default on Vista,
   but must be downloaded from MS for XP.  See
diff --git a/configure b/configure
index 5f0b76229..d9c20fd17 100755
--- a/configure
+++ b/configure
@@ -4375,7 +4375,63 @@ _ACEOF
 fi
 
     ;;
-  *-solaris2.0* | *-solaris2.1* | *-solaris2.2* | *-solaris2.3* | *-solaris2.4* | *-solaris2.5.1 )
+  *-solaris2.0*)
+    cat >>confdefs.h <<\_ACEOF
+#define STUPID_SOLARIS_CHECKSUM_BUG 1
+_ACEOF
+
+    cat >>confdefs.h <<\_ACEOF
+#define SOLARIS 1
+_ACEOF
+
+    ;;
+  *-solaris2.[1-9][0-9]*)
+    cat >>confdefs.h <<\_ACEOF
+#define SOLARIS 1
+_ACEOF
+
+    ;;
+  *-solaris2.1*)
+    cat >>confdefs.h <<\_ACEOF
+#define STUPID_SOLARIS_CHECKSUM_BUG 1
+_ACEOF
+
+    cat >>confdefs.h <<\_ACEOF
+#define SOLARIS 1
+_ACEOF
+
+    ;;
+  *-solaris2.2*)
+    cat >>confdefs.h <<\_ACEOF
+#define STUPID_SOLARIS_CHECKSUM_BUG 1
+_ACEOF
+
+    cat >>confdefs.h <<\_ACEOF
+#define SOLARIS 1
+_ACEOF
+
+    ;;
+  *-solaris2.3*)
+    cat >>confdefs.h <<\_ACEOF
+#define STUPID_SOLARIS_CHECKSUM_BUG 1
+_ACEOF
+
+    cat >>confdefs.h <<\_ACEOF
+#define SOLARIS 1
+_ACEOF
+
+    ;;
+  *-solaris2.4*)
+    cat >>confdefs.h <<\_ACEOF
+#define STUPID_SOLARIS_CHECKSUM_BUG 1
+_ACEOF
+
+    cat >>confdefs.h <<\_ACEOF
+#define SOLARIS 1
+_ACEOF
+
+    ;;
+  *-solaris2.5.1)
     cat >>confdefs.h <<\_ACEOF
 #define STUPID_SOLARIS_CHECKSUM_BUG 1
 _ACEOF
diff --git a/configure.ac b/configure.ac
index 663aab386..70c2e7d83 100644
--- a/configure.ac
+++ b/configure.ac
@@ -138,7 +138,30 @@ case "$host" in
     # on HP-UX 11.11 (other versions?) Mikhail Zakharov (zmey20000@yahoo.com)
     AC_CHECK_LIB(nm, open_mib)
     ;;
-  *-solaris2.0* | *-solaris2.1* | *-solaris2.2* | *-solaris2.3* | *-solaris2.4* | *-solaris2.5.1 )  
+  *-solaris2.0*)  
+    AC_DEFINE(STUPID_SOLARIS_CHECKSUM_BUG)
+    AC_DEFINE(SOLARIS)
+    ;;
+  *-solaris2.[[1-9]][[0-9]]*)
+    AC_DEFINE(SOLARIS)
+    ;;
+  *-solaris2.1*)
+    AC_DEFINE(STUPID_SOLARIS_CHECKSUM_BUG)
+    AC_DEFINE(SOLARIS)
+    ;;
+  *-solaris2.2*)
+    AC_DEFINE(STUPID_SOLARIS_CHECKSUM_BUG)
+    AC_DEFINE(SOLARIS)
+    ;;
+  *-solaris2.3*)
+    AC_DEFINE(STUPID_SOLARIS_CHECKSUM_BUG)
+    AC_DEFINE(SOLARIS)
+    ;;
+  *-solaris2.4*)
+    AC_DEFINE(STUPID_SOLARIS_CHECKSUM_BUG)
+    AC_DEFINE(SOLARIS)
+    ;;
+  *-solaris2.5.1)
     AC_DEFINE(STUPID_SOLARIS_CHECKSUM_BUG)
     AC_DEFINE(SOLARIS)
     ;;