diff --git a/configure b/configure
index 71bdea27..7414f7bc 100755
--- a/configure
+++ b/configure
@@ -558,6 +558,8 @@ ac_subst_vars='LTLIBOBJS
 LIBOBJS
 DATADIR
 MODDIR
+LIBICONV
+CHARSET
 SASL
 TCL_FLAGS
 EXTRA
@@ -3018,11 +3020,10 @@ pkg_failed=no
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for c_ares" >&5
 $as_echo_n "checking for c_ares... " >&6; }
 
-if test -n "$PKG_CONFIG"; then
-    if test -n "$c_ares_CFLAGS"; then
-        pkg_cv_c_ares_CFLAGS="$c_ares_CFLAGS"
-    else
-        if test -n "$PKG_CONFIG" && \
+if test -n "$c_ares_CFLAGS"; then
+    pkg_cv_c_ares_CFLAGS="$c_ares_CFLAGS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
     { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libcares\""; } >&5
   ($PKG_CONFIG --exists --print-errors "libcares") 2>&5
   ac_status=$?
@@ -3032,15 +3033,13 @@ if test -n "$PKG_CONFIG"; then
 else
   pkg_failed=yes
 fi
-    fi
-else
-	pkg_failed=untried
+ else
+    pkg_failed=untried
 fi
-if test -n "$PKG_CONFIG"; then
-    if test -n "$c_ares_LIBS"; then
-        pkg_cv_c_ares_LIBS="$c_ares_LIBS"
-    else
-        if test -n "$PKG_CONFIG" && \
+if test -n "$c_ares_LIBS"; then
+    pkg_cv_c_ares_LIBS="$c_ares_LIBS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
     { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libcares\""; } >&5
   ($PKG_CONFIG --exists --print-errors "libcares") 2>&5
   ac_status=$?
@@ -3050,9 +3049,8 @@ if test -n "$PKG_CONFIG"; then
 else
   pkg_failed=yes
 fi
-    fi
-else
-	pkg_failed=untried
+ else
+    pkg_failed=untried
 fi
 
 
@@ -3065,9 +3063,9 @@ else
         _pkg_short_errors_supported=no
 fi
         if test $_pkg_short_errors_supported = yes; then
-	        c_ares_PKG_ERRORS=`$PKG_CONFIG --short-errors --errors-to-stdout --print-errors "libcares"`
+	        c_ares_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors "libcares" 2>&1`
         else
-	        c_ares_PKG_ERRORS=`$PKG_CONFIG --errors-to-stdout --print-errors "libcares"`
+	        c_ares_PKG_ERRORS=`$PKG_CONFIG --print-errors "libcares" 2>&1`
         fi
 	# Put the nasty error message in config.log where it belongs
 	echo "$c_ares_PKG_ERRORS" >&5
@@ -3559,6 +3557,96 @@ $as_echo "$TCL_FLAGS" >&6; }
 	fi
 fi
 
+if test x"$EXTRA" = "xyes"
+then
+	ac_fn_cxx_check_func "$LINENO" "iconv" "ac_cv_func_iconv"
+if test "x$ac_cv_func_iconv" = x""yes; then :
+  CHARSET=1
+fi
+
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for iconv_open in -liconv" >&5
+$as_echo_n "checking for iconv_open in -liconv... " >&6; }
+if test "${ac_cv_lib_iconv_iconv_open+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-liconv  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char iconv_open ();
+int
+main ()
+{
+return iconv_open ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_link "$LINENO"; then :
+  ac_cv_lib_iconv_iconv_open=yes
+else
+  ac_cv_lib_iconv_iconv_open=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_iconv_iconv_open" >&5
+$as_echo "$ac_cv_lib_iconv_iconv_open" >&6; }
+if test "x$ac_cv_lib_iconv_iconv_open" = x""yes; then :
+  LIBICONV=-liconv ; CHARSET=1
+fi
+
+	if test "x$CHARSET" = "x1"
+	then
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether iconv expects a const second argument" >&5
+$as_echo_n "checking whether iconv expects a const second argument... " >&6; }
+		cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+
+		#include <iconv.h>
+
+int
+main ()
+{
+
+			const char input[] = "X"; const char *inptr = input; size_t inbytes = 1;
+			char buf[1]; char *outptr = buf; size_t outbytes = 1;
+			iconv_t ic = iconv_open("ISO8859-1", "UTF8");
+			iconv(ic, (char**)&inptr, &inbytes, &outptr, &outbytes);
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+
+			{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+			appendMod -DICONV_CONST=
+
+else
+
+			{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+			appendMod -DICONV_CONST=const
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+	else
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: libiconv was not found, disabling the charset module" >&5
+$as_echo "$as_me: WARNING: libiconv was not found, disabling the charset module" >&2;}
+	fi
+fi
+
 appendCXX "-D_MODDIR_=\\\"${MODDIR}\\\""
 appendCXX "-D_DATADIR_=\\\"${DATADIR}\\\""
 
@@ -3576,6 +3664,8 @@ appendCXX "-D_DATADIR_=\\\"${DATADIR}\\\""
 
 
 
+
+
 ac_config_files="$ac_config_files Makefile"
 
 ac_config_files="$ac_config_files znc-config"
diff --git a/configure.in b/configure.in
index b8b5c19d..0875b545 100644
--- a/configure.in
+++ b/configure.in
@@ -306,6 +306,33 @@ then
 	fi
 fi
 
+if test x"$EXTRA" = "xyes"
+then
+	AC_CHECK_FUNC( iconv, CHARSET=1 )
+	AC_CHECK_LIB( iconv, iconv_open, LIBICONV=-liconv ; CHARSET=1 )
+	if test "x$CHARSET" = "x1"
+	then
+		AC_MSG_CHECKING([whether iconv expects a const second argument])
+		AC_COMPILE_IFELSE([
+			AC_LANG_PROGRAM([[
+		#include <iconv.h>
+		]], [[
+			const char input[] = "X"; const char *inptr = input; size_t inbytes = 1;
+			char buf[1]; char *outptr = buf; size_t outbytes = 1;
+			iconv_t ic = iconv_open("ISO8859-1", "UTF8");
+			iconv(ic, (char**)&inptr, &inbytes, &outptr, &outbytes);
+		]])], [
+			AC_MSG_RESULT([no])
+			appendMod -DICONV_CONST=
+		], [
+			AC_MSG_RESULT([yes])
+			appendMod -DICONV_CONST=const
+		])
+	else
+		AC_MSG_WARN([libiconv was not found, disabling the charset module])
+	fi
+fi
+
 appendCXX "-D_MODDIR_=\\\"${MODDIR}\\\""
 appendCXX "-D_DATADIR_=\\\"${DATADIR}\\\""
 
@@ -321,6 +348,8 @@ AC_SUBST([NOSSL])
 AC_SUBST([EXTRA])
 AC_SUBST([TCL_FLAGS])
 AC_SUBST([SASL])
+AC_SUBST([CHARSET])
+AC_SUBST([LIBICONV])
 AC_SUBST([MODDIR])
 AC_SUBST([DATADIR])
 AC_CONFIG_FILES([Makefile])
diff --git a/modules/Makefile.in b/modules/Makefile.in
index 48a56142..cad46806 100644
--- a/modules/Makefile.in
+++ b/modules/Makefile.in
@@ -62,6 +62,11 @@ FILES    := $(shell echo $(FILES) | sed -e "s:extra/saslauth::")
 endif
 saslauthFLAGS := -lsasl2
 
+ifeq "@CHARSET@" ""
+FILES    := $(shell echo $(FILES) | sed -e "s:extra/charset::")
+endif
+charsetFLAGS := @LIBICONV@
+
 ifeq "$(TCL_FLAGS)" ""
 FILES       := $(shell echo $(FILES) | sed -e "s:extra/modtcl::")
 else
diff --git a/modules/extra/charset.cpp b/modules/extra/charset.cpp
index e9928465..a1020658 100644
--- a/modules/extra/charset.cpp
+++ b/modules/extra/charset.cpp
@@ -9,6 +9,13 @@
 #include "Modules.h"
 #include <iconv.h>
 
+#ifndef ICONV_CONST
+/* configure is supposed to define this, depending on whether the second
+	argument to iconv is const char** or just char**, but if it isn't defined,
+	we default to GNU/Linux which is non-const. */
+#define ICONV_CONST
+#endif
+
 class CCharsetMod : public CModule
 {
 private:
@@ -32,7 +39,7 @@ private:
 			bBreak = (uInLen < 1);
 
 			if(iconv(ic, // this is ugly, but keeps the code short:
-				(uInLen < 1 ? NULL : const_cast<char**>(&pIn)),
+				(uInLen < 1 ? NULL : (ICONV_CONST char**)&pIn),
 				(uInLen < 1 ? NULL : &uInLen),
 				&pOut, &uBufSize) == (size_t)-1)
 				// explanation: iconv needs a last call with input = NULL to
@@ -82,7 +89,7 @@ private:
 			const char* pIn = sData.c_str();
 			size_t uInLen = sData.size();
 
-			size_t uResult = iconv(ic, const_cast<char**>(&pIn), &uInLen, &pResultWalker, &uResultBufSize);
+			size_t uResult = iconv(ic, (ICONV_CONST char**)&pIn, &uInLen, &pResultWalker, &uResultBufSize);
 
 			iconv_close(ic);