diff --git a/pygmt/src/grdproject.py b/pygmt/src/grdproject.py
index 91e472e5496..2bf82e83dc6 100644
--- a/pygmt/src/grdproject.py
+++ b/pygmt/src/grdproject.py
@@ -116,8 +116,8 @@ def grdproject(
     >>> # Project the geographic gridded data onto a rectangular grid
     >>> new_grid = pygmt.grdproject(grid=grid, projection="M10c", region=region)
     """
-    if projection is None:
-        msg = "The projection must be specified."
+    if kwargs.get("J", projection) is None:
+        msg = "Parameter 'projection' must be specified."
         raise GMTInvalidInput(msg)
 
     aliasdict = AliasSystem().add_common(