diff --git a/ChangeLog b/ChangeLog
index 810015d..ab4e1cd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2007-04-30 Andrew J. Schorr <ajschorr@alumni.princeton.edu>
+
+	* configure.ac: Change gcc CFLAGS from '-std=c99' to '-std=gnu99'
+	  to improve portability.
+
 2007-04-29 Paul Jakma <paul.jakma@sun.com>
 
 	* configure.ac: Bump to 0.99.7
diff --git a/configure.ac b/configure.ac
index 5421c76..b24ab91 100755
--- a/configure.ac
+++ b/configure.ac
@@ -119,7 +119,7 @@
         AC_MSG_RESULT([Intel default])
         ;;
     "GCC")
-  	CFLAGS="-Os -fno-omit-frame-pointer -g -std=c99 -Wall"
+  	CFLAGS="-Os -fno-omit-frame-pointer -g -std=gnu99 -Wall"
   	CFLAGS="${CFLAGS} -Wsign-compare -Wpointer-arith"
   	CFLAGS="${CFLAGS} -Wbad-function-cast -Wwrite-strings"
   	CFLAGS="${CFLAGS} -Wmissing-prototypes -Wmissing-declarations"