diff --git a/src/grib2.h.in b/src/grib2.h.in
index f778e230..300e196c 100644
--- a/src/grib2.h.in
+++ b/src/grib2.h.in
@@ -289,7 +289,7 @@ g2int g2_gribend(unsigned char *cgrib);
 #define G2C_SECTION1_LEN 13 /**< Length of section 1 array. */
 
 /* Constants to help with templates. */
-#define G2C_MAX_GDS_TEMPLATE 32        /**< Maximum number of grid templates. */
+#define G2C_MAX_GDS_TEMPLATE 33        /**< Maximum number of grid templates. */
 #define G2C_MAX_GDS_TEMPLATE_MAPLEN 28 /**< Maximum grid template map length. */
 #define G2C_MAX_PDS_TEMPLATE 102        /**< Maximum number of PDS templates. */
 #define G2C_MAX_PDS_TEMPLATE_MAPLEN 50 /**< Maximum template map length. */
diff --git a/src/gridtemplates.c b/src/gridtemplates.c
index 2144c54b..86d709c2 100644
--- a/src/gridtemplates.c
+++ b/src/gridtemplates.c
@@ -123,6 +123,8 @@ static const struct gridtemplate templatesgrid[G2C_MAX_GDS_TEMPLATE] =
 
         /* 3.13: Mercator with modelling subdomains definition */
         {13, 23, 0, {1, 1, 4, 1, 4, 1, 4, 4, 4, -4, 4, 1, -4, -4, 4, 1, 4, 4, 4, 4, 4, 4, 4}}
+        /* 3.23: Polar stereographic projection with modelling subdomains definition */
+        {23, 22, 0, {1, 1, 4, 1, 4, 1, 4, 4, 4, -4, 4, 1, -4, 4, 4, 4, 1, 1, 4, 4, 4, 4}},
     };
 
 /**
diff --git a/tests/tst_get_grid_template.c b/tests/tst_get_grid_template.c
index 3a479bc6..de58bee1 100644
--- a/tests/tst_get_grid_template.c
+++ b/tests/tst_get_grid_template.c
@@ -7,7 +7,7 @@
 #include "grib2_int.h"
 
 /* Number of grid templates to test. */
-#define NUM_TESTS 32
+#define NUM_TESTS 33
 
 /* Number of grid templates with extensions. */
 #define NUM_EXT_TESTS 5
@@ -20,14 +20,14 @@ main()
     {
         int template_number[NUM_TESTS] = {
             0, 1, 2, 3, 4, 5, 12, 101, 140, 10, 20, 30, 31, 40, 41, 42, 43, 50, 51, 52, 53, 90, 100, 110, 120,
-            204, 32768, 32769, 1000, 1100, 1200, 13};
+            204, 32768, 32769, 1000, 1100, 1200, 13, 23};
         int expected_maplen[NUM_TESTS] = {
             19, 22, 22, 25, 13, 16, 22, 4, 17, 19, 18, 22, 22, 19, 22, 22, 25, 5, 8, 8, 11, 21, 11, 16, 7, 19,
-            19, 21, 20, 28, 16, 23};
+            19, 21, 20, 28, 16, 23. 22};
         int expected_needsext[NUM_TESTS] = {
-            0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,0, 1, 0, 0, 0, 1, 0, 1, 0};
+            0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,0, 1, 0, 0, 0, 1, 0, 1, 0, 0};
         int expected_extlen[NUM_TESTS] = {
-            0, 0, 0, 0, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 0, 2, 0};
+            0, 0, 0, 0, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 0, 2, 0, 0};
         int expected_map[NUM_TESTS][28] = {
             {1, 1, 4, 1, 4, 1, 4, 4, 4, 4, 4, -4, 4, 1, -4, 4, 4, 4, 1, 0, 0, 0},                      /* 0 */
             {1, 1, 4, 1, 4, 1, 4, 4, 4, 4, 4, -4, 4, 1, -4, 4, 4, 4, 1, -4, 4, 4, 0, 0, 0},            /* 1 */
@@ -61,6 +61,7 @@ main()
             {1, 1, 4, 1, 4, 1, 4, 4, 4, 4, -4, 4, 1, -4, 4, 1, 4, 1, -4, 1, 1, -4, 2, 1, 1, 1, 1, 1},  /* 1100 */
             {4, 1, -4, 1, 1, -4, 2, 1, 1, 1, 1, 1, 2, 1, 1, 2},                                        /* 1200 */
             {1, 1, 4, 1, 4, 1, 4, 4, 4, -4, 4, 1, -4, -4, 4, 1, 4, 4, 4, 4, 4, 4, 4},                  /* 13 */
+            {1, 1, 4, 1, 4, 1, 4, 4, 4, -4, 4, 1, -4, 4, 4, 4, 1, 1, 4, 4, 4, 4},                      /* 23 */
         };
         int expected_ext[NUM_EXT_TESTS][8] = {
             {4, 4, -4, -4},