diff --git a/m4/arc-gnome.m4 b/m4/arc-gnome.m4
index f247b8a..349d1e0 100644
--- a/m4/arc-gnome.m4
+++ b/m4/arc-gnome.m4
@@ -10,18 +10,16 @@ AC_DEFUN([ARC_GNOME], [
             [GNOME minor version]
         )],
         [GNOME_VERSION="$withval"],
-        [
-         AC_CHECK_PROG(HAVE_PKG_CONFIG, pkg-config, yes)
+        [AC_CHECK_PROG(HAVE_PKG_CONFIG, pkg-config, yes)
          AS_IF(
              [test "x$HAVE_PKG_CONFIG" != "xyes"],
              [AC_MSG_ERROR([Could not find pkg-config.])]
          )
          PKG_CHECK_EXISTS(
-            [gtk+-3.0],
-            [GNOME_VERSION=`$PKG_CONFIG --modversion gtk+-3.0`],
-            [AC_MSG_ERROR([Could not determine GNOME version. Please install GTK+3.0 and/or GTK+3.0 development files.])]
-          )
-        ]
+             [gtk+-3.0],
+             [GNOME_VERSION=`$PKG_CONFIG --modversion gtk+-3.0`],
+             [AC_MSG_ERROR([Could not determine GNOME version. Install GTK3 and its development files (libgtk-3-dev for Debian/Ubuntu based distros and gtk3-devel for RPM based distros).])]
+         )]
     )
 
     # Trim version extras