configure: fix spelling
diff --git a/configure.ac b/configure.ac
index 634d635..9c47b5b 100755
--- a/configure.ac
+++ b/configure.ac
@@ -1545,7 +1545,7 @@
 Quagga configuration
 --------------------
 quagga version          : ${PACKAGE_VERSION}
-host operationg system  : ${host_os}
+host operating system  : ${host_os}
 source code location    : ${srcdir}
 compiler                : ${CC}
 compiler flags          : ${CFLAGS}