diff --git a/src/potential/gmtgravmag3d.c b/src/potential/gmtgravmag3d.c
index fabd64a7e9a..36124ab9e6b 100644
--- a/src/potential/gmtgravmag3d.c
+++ b/src/potential/gmtgravmag3d.c
@@ -333,7 +333,7 @@ static int parse(struct GMT_CTRL *GMT, struct GMTGRAVMAG3D_CTRL *Ctrl, struct GM
 						if (n_par < 8)  Ctrl->M.params[BELL][nBELL][7] = Ctrl->npts_circ;
 						if (n_par < 9)  Ctrl->M.params[BELL][nBELL][8] = Ctrl->n_slices;
 						if (Ctrl->M.params[BELL][nBELL][6] || Ctrl->M.params[SPHERE][nSPHERE][7] <= 0 || Ctrl->M.params[SPHERE][nSPHERE][8] <= 0) {
-							GMT_Report (API, GMT_MSG_ERROR, "Bad parameters for the 'bell' body. Please, RTFM (read the manual).");
+							GMT_Report(API, GMT_MSG_ERROR, "Bad parameters for the 'bell' body. Please, read the manual.");
 							return GMT_PARSE_ERROR;
 						}
 						Ctrl->M.type[BELL][nBELL] = BELL;
@@ -344,7 +344,7 @@ static int parse(struct GMT_CTRL *GMT, struct GMTGRAVMAG3D_CTRL *Ctrl, struct GM
 						if (n_par < 3) err_npar = 1;
 						if (n_par < 6)  Ctrl->M.params[CYLINDER][nCIL][5] = Ctrl->npts_circ;
 						if (Ctrl->M.params[SPHERE][nSPHERE][5] <= 0) {
-							GMT_Report (API, GMT_MSG_ERROR, "Bad parameters for the 'cylinder' body. Please, RTFM (read the manual).");
+							GMT_Report(API, GMT_MSG_ERROR, "Bad parameters for the 'cylinder' body. Please, read the manual.");
 							return GMT_PARSE_ERROR;
 						}
 						Ctrl->M.type[CYLINDER][nCIL] = CYLINDER;
@@ -362,8 +362,8 @@ static int parse(struct GMT_CTRL *GMT, struct GMTGRAVMAG3D_CTRL *Ctrl, struct GM
 						if (n_par < 4) err_npar = 1;
 						if (n_par < 7)  Ctrl->M.params[ELLIPSOID][nELL][6] = Ctrl->npts_circ;
 						if (n_par < 8)  Ctrl->M.params[ELLIPSOID][nELL][7] = Ctrl->n_slices;
-						if (Ctrl->M.params[SPHERE][nSPHERE][6] <= 0 || Ctrl->M.params[SPHERE][nSPHERE][7] <= 0) {
-							GMT_Report (API, GMT_MSG_ERROR, "Bad parameters for the 'ellipsoid' body. Please, RTFM (read the manual).");
+						if (Ctrl->M.params[ELLIPSOID][nELL][6] <= 0 || Ctrl->M.params[ELLIPSOID][nELL][7] <= 0) {
+							GMT_Report (API, GMT_MSG_ERROR, "Bad parameters for the 'ellipsoid' body. Please, read the manual.");
 							return GMT_PARSE_ERROR;
 						}
 						Ctrl->M.type[ELLIPSOID][nELL] = ELLIPSOID;
@@ -387,7 +387,7 @@ static int parse(struct GMT_CTRL *GMT, struct GMTGRAVMAG3D_CTRL *Ctrl, struct GM
 						if (n_par < 5)  Ctrl->M.params[SPHERE][nSPHERE][4] = Ctrl->npts_circ;
 						if (n_par < 6)  Ctrl->M.params[SPHERE][nSPHERE][5] = Ctrl->n_slices;
 						if (Ctrl->M.params[SPHERE][nSPHERE][4] <= 0 || Ctrl->M.params[SPHERE][nSPHERE][5] <= 0) {
-							GMT_Report (API, GMT_MSG_ERROR, "Bad parameters for the 'sphere' body. Please, RTFM (read the manual).");
+							GMT_Report (API, GMT_MSG_ERROR, "Bad parameters for the 'sphere' body. Please, read the manual.");
 							return GMT_PARSE_ERROR;
 						}
 						Ctrl->M.type[SPHERE][nSPHERE] = SPHERE;
diff --git a/src/potential/solids.c b/src/potential/solids.c
index fb9537ae5ba..4a2f43b6fbb 100644
--- a/src/potential/solids.c
+++ b/src/potential/solids.c
@@ -143,6 +143,14 @@ int five_psoid(struct GMT_CTRL *GMT, struct GMTGRAVMAG3D_CTRL *Ctrl, int body_ty
 	a  = Ctrl->M.params[body_type][nb][0];		b   = Ctrl->M.params[body_type][nb][1];
 	c  = Ctrl->M.params[body_type][nb][2];		z_c = Ctrl->M.params[body_type][nb][3];
 	x0 = Ctrl->M.params[body_type][nb][4];		y0  = Ctrl->M.params[body_type][nb][5];
+	if (body_type == SPHERE) {		/* This has less parameters so the above is wrong. */
+		b = c = a;	z_c = Ctrl->M.params[body_type][nb][1];
+		x0 = Ctrl->M.params[body_type][nb][2];		y0 = Ctrl->M.params[body_type][nb][3];
+	}
+	if (body_type == BELL) {
+		a = b;	b = c;	c = Ctrl->M.params[body_type][nb][0];
+	}
+
 	z_top = z_c + c;	z_bot = z_c;
 
 	n_tri = (hemi) ? 2 * npts_circ * n_slices : 2 * (npts_circ * (n_slices*2 - 1));