diff --git a/configure b/configure
index 9b55590..c059d7c 100755
--- a/configure
+++ b/configure
@@ -6919,7 +6919,6 @@
 
 
 
-
 #
 # Enable run-time checking.
 #
@@ -8284,13 +8283,13 @@
 else
   lt_cv_nm_interface="BSD nm"
   echo "int some_variable = 0;" > conftest.$ac_ext
-  (eval echo "\"\$as_me:8287: $ac_compile\"" >&5)
+  (eval echo "\"\$as_me:8286: $ac_compile\"" >&5)
   (eval "$ac_compile" 2>conftest.err)
   cat conftest.err >&5
-  (eval echo "\"\$as_me:8290: $NM \\\"conftest.$ac_objext\\\"\"" >&5)
+  (eval echo "\"\$as_me:8289: $NM \\\"conftest.$ac_objext\\\"\"" >&5)
   (eval "$NM \"conftest.$ac_objext\"" 2>conftest.err > conftest.out)
   cat conftest.err >&5
-  (eval echo "\"\$as_me:8293: output\"" >&5)
+  (eval echo "\"\$as_me:8292: output\"" >&5)
   cat conftest.out >&5
   if $GREP 'External.*some_variable' conftest.out > /dev/null; then
     lt_cv_nm_interface="MS dumpbin"
@@ -9481,7 +9480,7 @@
   ;;
 *-*-irix6*)
   # Find out which ABI we are using.
-  echo '#line 9484 "configure"' > conftest.$ac_ext
+  echo '#line 9483 "configure"' > conftest.$ac_ext
   if { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_compile\""; } >&5
   (eval $ac_compile) 2>&5
   ac_status=$?
@@ -11566,11 +11565,11 @@
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:11569: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:11568: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>conftest.err)
    ac_status=$?
    cat conftest.err >&5
-   echo "$as_me:11573: \$? = $ac_status" >&5
+   echo "$as_me:11572: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s "$ac_outfile"; then
      # The compiler can only warn and ignore the option if not recognized
      # So say no if there are warnings other than the usual output.
@@ -11905,11 +11904,11 @@
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:11908: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:11907: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>conftest.err)
    ac_status=$?
    cat conftest.err >&5
-   echo "$as_me:11912: \$? = $ac_status" >&5
+   echo "$as_me:11911: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s "$ac_outfile"; then
      # The compiler can only warn and ignore the option if not recognized
      # So say no if there are warnings other than the usual output.
@@ -12010,11 +12009,11 @@
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:12013: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:12012: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>out/conftest.err)
    ac_status=$?
    cat out/conftest.err >&5
-   echo "$as_me:12017: \$? = $ac_status" >&5
+   echo "$as_me:12016: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s out/conftest2.$ac_objext
    then
      # The compiler can only warn and ignore the option if not recognized
@@ -12065,11 +12064,11 @@
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:12068: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:12067: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>out/conftest.err)
    ac_status=$?
    cat out/conftest.err >&5
-   echo "$as_me:12072: \$? = $ac_status" >&5
+   echo "$as_me:12071: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s out/conftest2.$ac_objext
    then
      # The compiler can only warn and ignore the option if not recognized
@@ -14435,7 +14434,7 @@
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 14438 "configure"
+#line 14437 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -14531,7 +14530,7 @@
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 14534 "configure"
+#line 14533 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -16487,11 +16486,11 @@
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:16490: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:16489: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>conftest.err)
    ac_status=$?
    cat conftest.err >&5
-   echo "$as_me:16494: \$? = $ac_status" >&5
+   echo "$as_me:16493: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s "$ac_outfile"; then
      # The compiler can only warn and ignore the option if not recognized
      # So say no if there are warnings other than the usual output.
@@ -16586,11 +16585,11 @@
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:16589: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:16588: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>out/conftest.err)
    ac_status=$?
    cat out/conftest.err >&5
-   echo "$as_me:16593: \$? = $ac_status" >&5
+   echo "$as_me:16592: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s out/conftest2.$ac_objext
    then
      # The compiler can only warn and ignore the option if not recognized
@@ -16638,11 +16637,11 @@
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:16641: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:16640: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>out/conftest.err)
    ac_status=$?
    cat out/conftest.err >&5
-   echo "$as_me:16645: \$? = $ac_status" >&5
+   echo "$as_me:16644: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s out/conftest2.$ac_objext
    then
      # The compiler can only warn and ignore the option if not recognized
@@ -18050,7 +18049,7 @@
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 18053 "configure"
+#line 18052 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
diff --git a/configure.ac b/configure.ac
index 631db07..912c05b 100755
--- a/configure.ac
+++ b/configure.ac
@@ -240,7 +240,7 @@
 #
 # Enable OS features.
 #
-AC_GNU_SOURCE
+AC_USE_SYSTEM_EXTENSIONS
 
 #
 # Enable run-time checking.