diff --git a/examples/C/bufr_copy_data.c b/examples/C/bufr_copy_data.c
index 589a7de1b..3bc8c7a39 100644
--- a/examples/C/bufr_copy_data.c
+++ b/examples/C/bufr_copy_data.c
@@ -93,7 +93,7 @@ int main(int argc, char* argv[])
             printf("Copied %s\n", keys[i]);
             free(keys[i]);
         }
-        printf("Total number of copied keys = %lu\n", (unsigned long)nkeys);
+        printf("Total number of copied keys = %zu\n", nkeys);
         free(keys);
 
         codes_handle_delete(h);
diff --git a/examples/C/bufr_expanded.c b/examples/C/bufr_expanded.c
index 838dd70a6..6d103f68f 100644
--- a/examples/C/bufr_expanded.c
+++ b/examples/C/bufr_expanded.c
@@ -57,7 +57,7 @@ int main(int argc, char* argv[])
 
         /* get the size of the values array*/
         CODES_CHECK(codes_get_size(h, "numericValues", &values_len), 0);
-        printf("  number of expanded values: %lu\n", (unsigned long)values_len);
+        printf("  number of expanded values: %zu\n", values_len);
 
         /* allocate array for data values */
         values = (double*)malloc(values_len * sizeof(double));
diff --git a/examples/C/bufr_get_string_array.c b/examples/C/bufr_get_string_array.c
index 43f499074..5568f924a 100644
--- a/examples/C/bufr_get_string_array.c
+++ b/examples/C/bufr_get_string_array.c
@@ -56,7 +56,7 @@ int main(int argc, char* argv[])
         for (i = 0; i < size; ++i) {
             printf("%s\n", strArray[i]);
         }
-        printf("stationOrSiteName string array size = %lu\n", (unsigned long)size);
+        printf("stationOrSiteName string array size = %zu\n", size);
 
         /* free allocated arrays */
         for (i = 0; i < size; ++i)
diff --git a/examples/C/bufr_keys_iterator.c b/examples/C/bufr_keys_iterator.c
index 1f739078d..47770e257 100644
--- a/examples/C/bufr_keys_iterator.c
+++ b/examples/C/bufr_keys_iterator.c
@@ -98,7 +98,7 @@ int main(int argc, char* argv[])
             }
             else {
                 /* for arrays */
-                printf("(array of %lu)\n", (unsigned long)klen);
+                printf("(array of %zu)\n", klen);
             }
         }
 
diff --git a/examples/C/bufr_read_temp.c b/examples/C/bufr_read_temp.c
index 86e84e999..baedebea9 100644
--- a/examples/C/bufr_read_temp.c
+++ b/examples/C/bufr_read_temp.c
@@ -84,7 +84,7 @@ int main(int argc, char* argv[])
         snprintf(key_name, sizeof(key_name), "/verticalSoundingSignificance=4/pressure");
         CODES_CHECK(codes_get_size(h, key_name, &sigt_len), 0);
 
-        printf("Number of T significant levels: %lu\n", (unsigned long)sigt_len);
+        printf("Number of T significant levels: %zu\n", sigt_len);
 
         /* allocate memory for the values to be read. Each
          * parameter must have the same number of values. */
diff --git a/examples/C/grib_ensemble_index.c b/examples/C/grib_ensemble_index.c
index aab96f64d..1e86aae0b 100644
--- a/examples/C/grib_ensemble_index.c
+++ b/examples/C/grib_ensemble_index.c
@@ -39,7 +39,7 @@ int main(int argc, char* argv[])
 
     /* get size of "paramId" list */
     CODES_CHECK(codes_index_get_size(index, "paramId", &paramIdSize), 0);
-    printf("grib contains %lu different parameters\n", (unsigned long)paramIdSize);
+    printf("grib contains %zu different parameters\n", paramIdSize);
     /* allocate memory for "paramId" list */
     paramId = (char**)malloc(paramIdSize * sizeof(char*));
     /* get list of "paramId" */
@@ -47,7 +47,7 @@ int main(int argc, char* argv[])
 
     /* get size of ensemble number list */
     CODES_CHECK(codes_index_get_size(index, "number", &numberSize), 0);
-    printf("GRIB contains %lu different ensemble members\n", (unsigned long)numberSize);
+    printf("GRIB contains %zu different ensemble members\n", numberSize);
     /* allocate memory for ensemble number list */
     number = (long*)malloc(numberSize * sizeof(long));
     /* get list of ensemble numbers */
diff --git a/examples/C/grib_index.c b/examples/C/grib_index.c
index 858757951..c93ef5b8f 100644
--- a/examples/C/grib_index.c
+++ b/examples/C/grib_index.c
@@ -64,7 +64,7 @@ int main(int argc, char* argv[])
     /* get the list of distinct steps from the index */
     /* the list is in ascending order */
     CODES_CHECK(codes_index_get_long(index, "step", steps, &stepSize), 0);
-    printf("stepSize=%ld\n", (long)stepSize);
+    printf("stepSize=%zu\n", stepSize);
     for (i = 0; i < stepSize; i++)
         printf("%ld ", steps[i]);
     printf("\n");
@@ -75,7 +75,7 @@ int main(int argc, char* argv[])
     if (!levels) exit(1);
     /*same as for "step"*/
     CODES_CHECK(codes_index_get_long(index, "level", levels, &levelSize), 0);
-    printf("levelSize=%ld\n", (long)levelSize);
+    printf("levelSize=%zu\n", levelSize);
     for (i = 0; i < levelSize; i++)
         printf("%ld ", levels[i]);
     printf("\n");
@@ -86,7 +86,7 @@ int main(int argc, char* argv[])
     if (!numbers) exit(1);
     /*same as for "step"*/
     CODES_CHECK(codes_index_get_long(index, "number", numbers, &numberSize), 0);
-    printf("numberSize=%ld\n", (long)numberSize);
+    printf("numberSize=%zu\n", numberSize);
     for (i = 0; i < numberSize; i++)
         printf("%ld ", numbers[i]);
     printf("\n");
@@ -97,7 +97,7 @@ int main(int argc, char* argv[])
     if (!shortName) exit(1);
     /*same as for "step"*/
     CODES_CHECK(codes_index_get_string(index, "shortName", shortName, &shortNameSize), 0);
-    printf("shortNameSize=%ld\n", (long)shortNameSize);
+    printf("shortNameSize=%zu\n", shortNameSize);
     for (i = 0; i < shortNameSize; i++)
         printf("%s ", shortName[i]);
     printf("\n");
diff --git a/examples/C/grib_iterator_bitmap.c b/examples/C/grib_iterator_bitmap.c
index 6cf21b1d1..5060dc43c 100644
--- a/examples/C/grib_iterator_bitmap.c
+++ b/examples/C/grib_iterator_bitmap.c
@@ -55,7 +55,7 @@ int main(int argc, char** argv)
             CODES_CHECK(codes_get_size(h, "bitmap", &bmp_len), 0);
             bitmap = (long*)malloc(bmp_len * sizeof(long));
             CODES_CHECK(codes_get_long_array(h, "bitmap", bitmap, &bmp_len), 0);
-            printf("Bitmap is present. Num = %lu\n", (unsigned long)bmp_len);
+            printf("Bitmap is present. Num = %zu\n", bmp_len);
         }
         /* sanity check. Number of values must match number in bitmap */
         CODES_CHECK(codes_get_size(h, "values", &values_len), 0);
diff --git a/examples/C/grib_list.c b/examples/C/grib_list.c
index 403d0ce42..c5e1e71f0 100644
--- a/examples/C/grib_list.c
+++ b/examples/C/grib_list.c
@@ -65,7 +65,7 @@ int main(int argc, char** argv)
 
     /* get as a long*/
     CODES_CHECK(codes_get_size(h, "scaledValueOfCentralWaveNumber", &count), 0);
-    printf("count=%ld\n", (long)count);
+    printf("count=%zu\n", count);
 
     assert(count < sizeof(values) / sizeof(values[0]));
 
@@ -74,7 +74,7 @@ int main(int argc, char** argv)
     assert(size == count);
 
     for (i = 0; i < count; i++) {
-        printf("scaledValueOfCentralWaveNumber %lu = %ld\n", (unsigned long)i, values[i]);
+        printf("scaledValueOfCentralWaveNumber %zu = %ld\n", i, values[i]);
         if (i == 0) assert(values[i] == 26870);
         if (i == 1) assert(values[i] == 9272);
     }
@@ -91,7 +91,7 @@ int main(int argc, char** argv)
     CODES_CHECK(codes_get_long_array(h, "scaledValueOfCentralWaveNumber", new_values, &size), 0);
     assert(size == count);
     for (i = 0; i < count; i++) {
-        printf("Now scaledValueOfCentralWaveNumber %lu = %ld\n", (unsigned long)i, new_values[i]);
+        printf("Now scaledValueOfCentralWaveNumber %zu = %ld\n", i, new_values[i]);
         assert(new_values[i] == (i + 1000));
     }
 
diff --git a/examples/C/new_sample.c b/examples/C/new_sample.c
index 0e483c472..529b52b29 100644
--- a/examples/C/new_sample.c
+++ b/examples/C/new_sample.c
@@ -233,7 +233,7 @@ int main(int argc, char** argv)
     size    = 496;
     vdouble = (double*)calloc(size, sizeof(double));
     if (!vdouble) {
-        fprintf(stderr, "failed to allocate %lu bytes\n", (unsigned long)(size * sizeof(double)));
+        fprintf(stderr, "failed to allocate %zu bytes\n", size * sizeof(double));
         exit(1);
     }