diff --git a/configure.ac b/configure.ac
index f325f80..ffb5a82 100644
--- a/configure.ac
+++ b/configure.ac
@@ -70,7 +70,7 @@ CPPFLAGS="$CPPFLAGS -I$withval/include";
 CXXFLAGS="$CXXFLAGS -I$withval/include";
 LDFLAGS="$LDFLAGS -L$withval/lib",
 if test "$prefix" != "NONE"; then
-  CPPFLAGS="$CPPLAGS -I$prefix/include";
+  CPPFLAGS="$CPPFLAGS -I$prefix/include";
   CXXFLAGS="$CXXFLAGS -I$prefix/include";
   LDFLAGS="$LDFLAGS -L$prefix/lib"
 fi)
diff --git a/hacking/ChangeLog b/hacking/ChangeLog
index 4de5570..b72e6cb 100644
--- a/hacking/ChangeLog
+++ b/hacking/ChangeLog
@@ -416,3 +416,5 @@
 20130516 ChangeLog: update date in main changelog.
 20130517 README: update date for 1.1 release.
 20130518 man/fmfconv.1: update date for 1.1 release (Sergio).
+20130520 configure.ac: fix typo in the CPPFLAGS variable name (patch #310)
+         (Alberto).