diff --git a/ChangeLog b/ChangeLog
index 616a33c9..58cec6f6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,6 @@
 30/6/14 started 7.40.3
 - fix interlaced thumbnails in vipsthumbnail, thanks lovell
+- fix use of "header" in benchmark/, thanks David
 
 25/6/14 started 7.40.2
 - dzsave write to zip stops at 4gb, thanks bgilbert
diff --git a/benchmark/benchmarkn-osx.sh b/benchmark/benchmarkn-osx.sh
index 5eaff5b5..8642383a 100755
--- a/benchmark/benchmarkn-osx.sh
+++ b/benchmark/benchmarkn-osx.sh
@@ -21,8 +21,8 @@ if [ $? != 0 ]; then
   echo "build of test image failed -- out of disc space?"
   exit 1
 fi
-echo -n "test image is" `header -f width temp.v` 
-echo " by" `header -f height temp.v` "pixels"
+echo -n "test image is" `vipsheader -f width temp.v` 
+echo " by" `vipsheader -f height temp.v` "pixels"
 max_cpus=`vips im_concurrency_get`
 
 echo "max cpus = $max_cpus"
diff --git a/benchmark/benchmarkn.sh b/benchmark/benchmarkn.sh
index 9fdbcff6..c3b8cc21 100755
--- a/benchmark/benchmarkn.sh
+++ b/benchmark/benchmarkn.sh
@@ -21,8 +21,8 @@ if [ $? != 0 ]; then
   echo "build of test image failed -- out of disc space?"
   exit 1
 fi
-echo -n "test image is" `header -f width temp.v` 
-echo " by" `header -f height temp.v` "pixels"
+echo -n "test image is" `vipsheader -f width temp.v` 
+echo " by" `vipsheader -f height temp.v` "pixels"
 max_cpus=`vips im_concurrency_get`
 
 echo "max cpus = $max_cpus"
diff --git a/libvips/iofuncs/system.c b/libvips/iofuncs/system.c
index 690a3e95..55df343e 100644
--- a/libvips/iofuncs/system.c
+++ b/libvips/iofuncs/system.c
@@ -197,7 +197,7 @@ vips_system_build( VipsObject *object )
 			VIPS_FREE( std_output );
 		}
 		vips_error_system( result, class->nickname, 
-			"%s", _( "command failed" ) ); 
+			_( "command \"%s\" failed" ), cmd ); 
 
 		return( -1 ); 
 	}