diff --git a/configure.ac b/configure.ac
index 35fabcc..efa4018 100644
--- a/configure.ac
+++ b/configure.ac
@@ -25,14 +25,14 @@ AC_INIT([sgpemv2],[0.3],[matteo@member.fsf.org])
 if test -f "`pwd`/configure.ac"; then
         AC_MSG_FAILURE([
    ** This seems to be the pkg root directory.
-	** Compiling here your sources is considered
-	** as unpolite as exploring your nose with 
-	** your pinky whilst attending a wedding party.
+   ** Compiling here your sources is considered
+   ** as unpolite as exploring your nose with 
+   ** your pinky whilst attending a wedding party.
    ** Please create a new dir as described in
    ** the README file, and then run configure
    ** into it. If you think you've got it right, 
-	** please inform the mantainer of this error!
-	** He'll thoroughfully bash his head on the wall.], 
+   ** please inform the mantainer of this error!
+   ** He'll thoroughfully bash his head on the wall.], 
 	-1 )
 fi
 
@@ -73,7 +73,7 @@ dnl make
 AC_PROG_MAKE_SET
 
 dnl check for gtkmm & cairo
-PKG_PROG_PKG_CONFIG([0.20])
+PKG_PROG_PKG_CONFIG([0.19])
 if test -z "$PKG_CONFIG"; then
    AC_MSG_ERROR([You may need to update your pkg-config installation])
 fi