diff --git a/doc/rst/source/psconvert.rst b/doc/rst/source/psconvert.rst
index 254d1c45314..67fa7361b74 100644
--- a/doc/rst/source/psconvert.rst
+++ b/doc/rst/source/psconvert.rst
@@ -235,7 +235,8 @@ Optional Arguments
     sets **-A** **-P**.
 
     Use **-W+k** to create a minimalist KML file that allows loading the
-    image in GoogleEarth. Note that for this option the image must be in
+    image in GoogleEarth. Note that for this option to work it is necessary that the postscript
+    image must have been created with **-JX** or **-Jx** cartesian projection of
     geographical coordinates. If not, a warning is issued but the KML
     file is created anyway. Several modifier options are available to
     customize the KML file in the form of **+**\ *opt* strings. Append
diff --git a/src/psconvert.c b/src/psconvert.c
index 7d7cce60f10..fb6361882c4 100644
--- a/src/psconvert.c
+++ b/src/psconvert.c
@@ -23,7 +23,6 @@
  * psconvert uses the ideas of the EPS2XXX.m from Primoz Cermelj published in MatLab Central
  * and of psbbox.sh of Remko Scharroo.
  *
- *
  *--------------------------------------------------------------------*/
 /*
  * Authors:	Joaquim Luis and Remko Scharroo
@@ -2079,8 +2078,8 @@ EXTERN_MSC int GMT_psconvert (void *V_API, int mode, void *args) {
 					}
 				}
 				else if (Ctrl->W.kml) {
-					GMT_Report (API, GMT_MSG_ERROR, "To GE images must be in geographical coordinates. Very likely "
-								"this won't work as you wish inside GE.\n");
+					GMT_Report (API, GMT_MSG_ERROR, "To GE images must be in geographical coordinates (-JXd projected). "
+								"Very likely this won't work as you wish inside GE.\n");
 				}
 			}
 			else if (!strncmp (line, "%GMTBoundingBox:", 16)) {