diff --git a/m4/ipopt.m4 b/m4/ipopt.m4
index f6bf43dfd72541329bdf6498055203fba0bee202..a01f5377d4c5525b90f8e1c118fb44ea59bfdca1 100644
--- a/m4/ipopt.m4
+++ b/m4/ipopt.m4
@@ -13,56 +13,53 @@ ac_save_LIBS="$LIBS"
 
 ## do nothing if --without-amiramesh is used
 if test x$with_ipopt != xno ; then
-
-# is --with-ipopt=bla used?
-if test "x$with_ipopt" != x ; then
-    if ! test -d $with_ipopt; then
-        AC_MSG_WARN([IPOpt directory $with_ipopt does not exist])
-    else
-        # expand tilde / other stuff
-        IPOPTROOT=`cd $with_ipopt && pwd`
+    # is --with-ipopt=bla used?
+    if test "x$with_ipopt" != x ; then
+        if ! test -d $with_ipopt; then
+            AC_MSG_WARN([IPOpt directory $with_ipopt does not exist])
+        else
+            # expand tilde / other stuff
+            IPOPTROOT=`cd $with_ipopt && pwd`
+        fi
+    fi
+    if test "x$IPOPTROOT" = x; then
+	# use some default value...
+	IPOPTROOT="/usr/local/ipopt"
     fi
-fi
-if test "x$IPOPTROOT" = x; then
-    # use some default value...
-    IPOPTROOT="/usr/local/ipopt"
-fi
 
-IPOPT_LIB_PATH="$IPOPTROOT/lib"
-IPOPT_INCLUDE_PATH="$IPOPTROOT/include"
+    IPOPT_LIB_PATH="$IPOPTROOT/lib"
+    IPOPT_INCLUDE_PATH="$IPOPTROOT/include"
 
-LDFLAGS="$LDFLAGS -L$IPOPT_LIB_PATH"
-CPPFLAGS="$CPPFLAGS -I$IPOPT_INCLUDE_PATH"
+    LDFLAGS="$LDFLAGS -L$IPOPT_LIB_PATH"
+    CPPFLAGS="$CPPFLAGS -I$IPOPT_INCLUDE_PATH"
 
-# Check whether ipopt is installed at all
-if PKG_CONFIG_PATH=$IPOPT_LIB_PATH/pkgconfig $PKG_CONFIG --exists ipopt; then
-    IPOPT_CPPFLAGS="-I$IPOPT_INCLUDE_PATH"
-    HAVE_IPOPT="1"
-else
-    AC_MSG_WARN([IPOpt not found in $IPOPT_ROOT])
-fi
+    # Check whether ipopt is installed at all
+    if PKG_CONFIG_PATH=$IPOPT_LIB_PATH/pkgconfig $PKG_CONFIG --exists ipopt; then
+	IPOPT_CPPFLAGS="-I$IPOPT_INCLUDE_PATH"
+	HAVE_IPOPT="1"
+    else
+	AC_MSG_WARN([IPOpt not found in $IPOPT_ROOT])
+    fi
 
 
-AC_LANG_PUSH([C++])
+    AC_LANG_PUSH([C++])
 
-CPPFLAGS="$IPOPT_CPPFLAGS"
+    CPPFLAGS="$IPOPT_CPPFLAGS"
 
-# if header is found...
-if test x$HAVE_IPOPT = x1 ; then
-   LIBS="$LIBS `PKG_CONFIG_PATH=$IPOPT_LIB_PATH/pkgconfig $PKG_CONFIG --libs ipopt`"
-
-   AC_LINK_IFELSE(AC_LANG_PROGRAM(
-        [#include "coin/IpIpoptApplication.hpp"],
-        [Ipopt::SmartPtr<Ipopt::IpoptApplication> app = new Ipopt::IpoptApplication();]),
-    [IPOPT_LIBS="`PKG_CONFIG_PATH=$IPOPT_LIB_PATH/pkgconfig $PKG_CONFIG --libs-only-l ipopt`"
-         IPOPT_LDFLAGS="`PKG_CONFIG_PATH=$IPOPT_LIB_PATH/pkgconfig $PKG_CONFIG --libs-only-L ipopt`"],
-    [HAVE_IPOPT="0"
-    AC_MSG_WARN(IPOpt not found!)])
-fi
+    # if header is found...
+    if test x$HAVE_IPOPT = x1 ; then
+       LIBS="$LIBS `PKG_CONFIG_PATH=$IPOPT_LIB_PATH/pkgconfig $PKG_CONFIG --libs ipopt`"
 
-AC_LANG_POP([C++])
+       AC_LINK_IFELSE(AC_LANG_PROGRAM(
+	    [#include "coin/IpIpoptApplication.hpp"],
+	    [Ipopt::SmartPtr<Ipopt::IpoptApplication> app = new Ipopt::IpoptApplication();]),
+	[IPOPT_LIBS="`PKG_CONFIG_PATH=$IPOPT_LIB_PATH/pkgconfig $PKG_CONFIG --libs-only-l ipopt`"
+	     IPOPT_LDFLAGS="`PKG_CONFIG_PATH=$IPOPT_LIB_PATH/pkgconfig $PKG_CONFIG --libs-only-L ipopt`"],
+	[HAVE_IPOPT="0"
+	AC_MSG_WARN(IPOpt not found!)])
+    fi
 
-## end of ipopt check (--without wasn't set)
+    AC_LANG_POP([C++])
 fi
 
 with_ipopt="no"