diff --git a/qpms/lattices.h b/qpms/lattices.h
index dd6f547..ac00348 100644
--- a/qpms/lattices.h
+++ b/qpms/lattices.h
@@ -106,7 +106,7 @@ typedef struct PGenSphClassInfo { // static PGenSph info
 
 // TOP DATA STRUCTURE DEFINITION HERE
 typedef struct PGenSph {
-	const PGenSphClassInfo * const c;
+	const PGenSphClassInfo * /*const*/ c;
 	void *stateData; // shall be NULL if invalid (destroyed)
 } PGenSph;
 
diff --git a/tests/test_latticegens.c b/tests/test_latticegens.c
new file mode 100644
index 0000000..e9750ec
--- /dev/null
+++ b/tests/test_latticegens.c
@@ -0,0 +1,38 @@
+//c99 -o test_latticegens -ggdb -Wall -I ../ test_latticegens.c ../qpms/latticegens.c -lm
+
+#include <qpms/lattices.h>
+#include <stdio.h>
+
+void print_PGenSphReturnData(PGenSphReturnData d) {
+  sph_t s = d.point_sph;
+  cart3_t c = sph2cart(s);
+  printf("sph: (%g, %g π, %g π), cart: (%g, %g, %g), flags: %#xd\n",
+      s.r, s.theta / M_PI, s.phi / M_PI, c.x, c.y, c.z, d.flags);
+}
+
+void dump_PGenSph(PGenSph *g) {
+  PGenSphReturnData d;
+  do {
+    d = PGenSph_next(g);
+    print_PGenSphReturnData(d);
+  } while (d.flags & PGEN_NOTDONE);
+}
+
+#define DO_AND_PRINT(label, s) printf(#label ":\n" #s "\n"); s ;
+
+int main(int argc, char **argv) {
+  PGenSph g;
+  DO_AND_PRINT(test1a, g = PGenSph_zAxis_new_minMaxR(0.2, 0.14, 5, true,  7, true, PGENSPH_ZAXIS_INC_FROM_ORIGIN))
+  dump_PGenSph(&g);
+  DO_AND_PRINT(test1b, g = PGenSph_zAxis_new_minMaxR(0.2, 0.14, 5, true,  7, true, PGENSPH_ZAXIS_INC_TOWARDS_ORIGIN))
+  dump_PGenSph(&g);
+  DO_AND_PRINT(test2a, g = PGenSph_zAxis_new_minMaxR(0.2, 0.05, 5.05, true, 7.05, true, PGENSPH_ZAXIS_INC_FROM_ORIGIN))
+  dump_PGenSph(&g);
+  DO_AND_PRINT(test2b, g = PGenSph_zAxis_new_minMaxR(0.2, 0.05, 5.05, true, 7.05, true, PGENSPH_ZAXIS_INC_TOWARDS_ORIGIN))
+  dump_PGenSph(&g);
+  DO_AND_PRINT(test3a, g = PGenSph_zAxis_new_minMaxR(0.2, 0.05, 5.05, false, 7.05, false, PGENSPH_ZAXIS_INC_FROM_ORIGIN))
+  dump_PGenSph(&g);
+  DO_AND_PRINT(test3b, g = PGenSph_zAxis_new_minMaxR(0.2, 0.05, 5.05, false, 7.05, false, PGENSPH_ZAXIS_INC_TOWARDS_ORIGIN))
+  dump_PGenSph(&g);
+}
+