diff --git a/src/grib_accessor_class_bufr_data_element.c b/src/grib_accessor_class_bufr_data_element.c
index 004b705c4..75efd13e6 100644
--- a/src/grib_accessor_class_bufr_data_element.c
+++ b/src/grib_accessor_class_bufr_data_element.c
@@ -321,8 +321,9 @@ static int pack_string_array(grib_accessor* a, const char** v, size_t* len)
 {
     grib_accessor_bufr_data_element* self = (grib_accessor_bufr_data_element*)a;
 
-    int ret         = 0, i, idx;
-    char* s         = NULL;
+    int ret = GRIB_SUCCESS, idx = 0;
+    size_t i = 0;
+    char* s  = NULL;
     grib_context* c = a->context;
 
     if (self->compressedData) {
@@ -420,7 +421,7 @@ static int pack_string(grib_accessor* a, const char* val, size_t* len)
 {
     grib_accessor_bufr_data_element* self = (grib_accessor_bufr_data_element*)a;
 
-    int ret         = 0, idx;
+    int ret         = GRIB_SUCCESS, idx = 0;
     char* s         = NULL;
     grib_context* c = a->context;
 
@@ -442,8 +443,8 @@ static int pack_string(grib_accessor* a, const char* val, size_t* len)
 static int unpack_long(grib_accessor* a, long* val, size_t* len)
 {
     grib_accessor_bufr_data_element* self = (grib_accessor_bufr_data_element*)a;
-    int ret                               = 0, i;
-    long count                            = 0;
+    int ret    = GRIB_SUCCESS;
+    long count = 0, i = 0;
 
     value_count(a, &count);
 
@@ -471,8 +472,8 @@ static int unpack_long(grib_accessor* a, long* val, size_t* len)
 static int unpack_double(grib_accessor* a, double* val, size_t* len)
 {
     grib_accessor_bufr_data_element* self = (grib_accessor_bufr_data_element*)a;
-    int ret                               = 0, i;
-    long count                            = 0;
+    int ret = GRIB_SUCCESS;
+    long count = 0, i = 0;
 
     value_count(a, &count);
 
@@ -500,9 +501,9 @@ static int unpack_double(grib_accessor* a, double* val, size_t* len)
 static int pack_double(grib_accessor* a, const double* val, size_t* len)
 {
     grib_accessor_bufr_data_element* self = (grib_accessor_bufr_data_element*)a;
-    int ret                               = 0, i;
-    long count                            = 1;
-    grib_context* c                       = a->context;
+    int ret = GRIB_SUCCESS;
+    long count = 1, i = 0;
+    grib_context* c = a->context;
 
     if (self->compressedData) {
         count = *len;
diff --git a/src/grib_context.c b/src/grib_context.c
index 5e311606f..c2c49aa92 100644
--- a/src/grib_context.c
+++ b/src/grib_context.c
@@ -84,7 +84,7 @@ static void* default_long_lasting_malloc(const grib_context* c, size_t size)
     void* ret;
     ret = malloc(size);
     if (!ret) {
-        grib_context_log(c, GRIB_LOG_FATAL, "default_long_lasting_malloc: error allocating %lu bytes", (unsigned long)size);
+        grib_context_log(c, GRIB_LOG_FATAL, "default_long_lasting_malloc: error allocating %zu bytes", size);
         Assert(0);
     }
     return ret;
@@ -100,7 +100,7 @@ static void* default_buffer_malloc(const grib_context* c, size_t size)
     void* ret;
     ret = malloc(size);
     if (!ret) {
-        grib_context_log(c, GRIB_LOG_FATAL, "default_buffer_malloc: error allocating %lu bytes", (unsigned long)size);
+        grib_context_log(c, GRIB_LOG_FATAL, "default_buffer_malloc: error allocating %zu bytes", size);
         Assert(0);
     }
     return ret;
@@ -111,7 +111,7 @@ static void* default_buffer_realloc(const grib_context* c, void* p, size_t size)
     void* ret;
     ret = realloc(p, size);
     if (!ret) {
-        grib_context_log(c, GRIB_LOG_FATAL, "default_buffer_realloc: error allocating %lu bytes", (unsigned long)size);
+        grib_context_log(c, GRIB_LOG_FATAL, "default_buffer_realloc: error allocating %zu bytes", size);
         Assert(0);
     }
     return ret;
@@ -127,7 +127,7 @@ static void* default_malloc(const grib_context* c, size_t size)
     void* ret;
     ret = malloc(size);
     if (!ret) {
-        grib_context_log(c, GRIB_LOG_FATAL, "default_malloc: error allocating %lu bytes", (unsigned long)size);
+        grib_context_log(c, GRIB_LOG_FATAL, "default_malloc: error allocating %zu bytes", size);
         Assert(0);
     }
     return ret;
@@ -138,7 +138,7 @@ static void* default_realloc(const grib_context* c, void* p, size_t size)
     void* ret;
     ret = realloc(p, size);
     if (!ret) {
-        grib_context_log(c, GRIB_LOG_FATAL, "default_realloc: error allocating %lu bytes", (unsigned long)size);
+        grib_context_log(c, GRIB_LOG_FATAL, "default_realloc: error allocating %zu bytes", size);
         Assert(0);
     }
     return ret;
@@ -905,7 +905,7 @@ void* grib_context_malloc_persistent(const grib_context* c, size_t size)
     void* p = c->alloc_persistent_mem(c, size);
     if (!p) {
         grib_context_log(c, GRIB_LOG_FATAL,
-                         "grib_context_malloc_persistent: error allocating %lu bytes", (unsigned long)size);
+                         "grib_context_malloc_persistent: error allocating %zu bytes", size);
         Assert(0);
     }
     return p;
@@ -937,7 +937,7 @@ void* grib_context_malloc(const grib_context* c, size_t size)
     else
         p = c->alloc_mem(c, size);
     if (!p) {
-        grib_context_log(c, GRIB_LOG_FATAL, "grib_context_malloc: error allocating %lu bytes", (unsigned long)size);
+        grib_context_log(c, GRIB_LOG_FATAL, "grib_context_malloc: error allocating %zu bytes", size);
         Assert(0);
     }
     return p;
@@ -950,7 +950,7 @@ void* grib_context_realloc(const grib_context* c, void* p, size_t size)
         c = grib_context_get_default();
     q = c->realloc_mem(c, p, size);
     if (!q) {
-        grib_context_log(c, GRIB_LOG_FATAL, "grib_context_realloc: error allocating %lu bytes", (unsigned long)size);
+        grib_context_log(c, GRIB_LOG_FATAL, "grib_context_realloc: error allocating %zu bytes", size);
         return NULL;
     }
     return q;
@@ -985,7 +985,7 @@ void* grib_context_buffer_malloc(const grib_context* c, size_t size)
     else
         p = c->alloc_buffer_mem(c, size);
     if (!p) {
-        grib_context_log(c, GRIB_LOG_FATAL, "grib_context_buffer_malloc: error allocating %lu bytes", (unsigned long)size);
+        grib_context_log(c, GRIB_LOG_FATAL, "grib_context_buffer_malloc: error allocating %zu bytes", size);
         return NULL;
     }
     return p;
@@ -1003,7 +1003,7 @@ void* grib_context_buffer_realloc(const grib_context* c, void* p, size_t size)
 {
     void* q = c->realloc_buffer_mem(c, p, size);
     if (!q) {
-        grib_context_log(c, GRIB_LOG_FATAL, "grib_context_buffer_realloc: error allocating %lu bytes", (unsigned long)size);
+        grib_context_log(c, GRIB_LOG_FATAL, "grib_context_buffer_realloc: error allocating %zu bytes", size);
         return NULL;
     }
     return q;
diff --git a/src/grib_darray.c b/src/grib_darray.c
index bc7c8dab1..e37ba710f 100644
--- a/src/grib_darray.c
+++ b/src/grib_darray.c
@@ -15,9 +15,9 @@ void grib_darray_print(const char* title, const grib_darray* darray)
 {
     size_t i;
     Assert(darray);
-    printf("%s: darray.n=%lu  \t", title, (unsigned long)darray->n);
+    printf("%s: darray.n=%zu  \t", title, darray->n);
     for (i = 0; i < darray->n; i++) {
-        printf("darray[%lu]=%g\t", (unsigned long)i, darray->v[i]);
+        printf("darray[%zu]=%g\t", i, darray->v[i]);
     }
     printf("\n");
 }
diff --git a/src/grib_iarray.c b/src/grib_iarray.c
index 67f644865..39f1439e1 100644
--- a/src/grib_iarray.c
+++ b/src/grib_iarray.c
@@ -9,9 +9,7 @@
  */
 
 /***************************************************************************
- *
  *   Enrico Fucile
- *
  ***************************************************************************/
 
 #include "grib_api_internal.h"
@@ -21,9 +19,9 @@ void grib_iarray_print(const char* title, const grib_iarray* iarray)
 {
     size_t i;
     Assert(iarray);
-    printf("%s: iarray.n=%lu  \t", title, (unsigned long)iarray->n);
+    printf("%s: iarray.n=%zu  \t", title, iarray->n);
     for (i = 0; i < iarray->n; i++) {
-        printf("iarray[%lu]=%ld\t", (unsigned long)i, iarray->v[i]);
+        printf("iarray[%zu]=%ld\t", i, iarray->v[i]);
     }
     printf("\n");
 }
diff --git a/src/grib_util.c b/src/grib_util.c
index 362a4e168..e017e6d4e 100644
--- a/src/grib_util.c
+++ b/src/grib_util.c
@@ -384,7 +384,7 @@ static void print_values(grib_context* c,
     size_t i       = 0;
     int isConstant = 1;
     double v = 0, minVal = DBL_MAX, maxVal = -DBL_MAX;
-    fprintf(stderr, "ECCODES DEBUG grib_util: grib_set_values, setting %lu key/value pairs\n", (unsigned long)count);
+    fprintf(stderr, "ECCODES DEBUG grib_util: grib_set_values, setting %zu key/value pairs\n", count);
 
     for (i = 0; i < count; i++) {
         switch (keyval_pairs[i].type) {
@@ -400,7 +400,7 @@ static void print_values(grib_context* c,
         }
     }
 
-    fprintf(stderr, "ECCODES DEBUG grib_util: data_values_count=%lu;\n", (unsigned long)data_values_count);
+    fprintf(stderr, "ECCODES DEBUG grib_util: data_values_count=%zu;\n", data_values_count);
     for (i = 0; i < data_values_count; i++) {
         if (i == 0)
             v = data_values[i];
diff --git a/src/grib_vdarray.c b/src/grib_vdarray.c
index 4063eb19a..3510bf77c 100644
--- a/src/grib_vdarray.c
+++ b/src/grib_vdarray.c
@@ -22,9 +22,9 @@ void grib_vdarray_print(const char* title, const grib_vdarray* vdarray)
     size_t i = 0;
     char text[100] = {0,};
     Assert(vdarray);
-    printf("%s: vdarray.n=%lu\n", title, (unsigned long)vdarray->n);
+    printf("%s: vdarray.n=%zu\n", title, vdarray->n);
     for (i = 0; i < vdarray->n; i++) {
-        snprintf(text, sizeof(text), " vdarray->v[%lu]", (unsigned long)i);
+        snprintf(text, sizeof(text), " vdarray->v[%zu]", i);
         grib_darray_print(text, vdarray->v[i]);
     }
     printf("\n");
diff --git a/src/grib_viarray.c b/src/grib_viarray.c
index 336e375bf..dde75f8de 100644
--- a/src/grib_viarray.c
+++ b/src/grib_viarray.c
@@ -23,9 +23,9 @@ void grib_viarray_print(const char* title, const grib_viarray* viarray)
     char text[100] = {0,};
     const size_t textLen = sizeof(text);
     Assert(viarray);
-    printf("%s: viarray.n=%lu\n", title, (unsigned long)viarray->n);
+    printf("%s: viarray.n=%zu\n", title, viarray->n);
     for (i = 0; i < viarray->n; i++) {
-        snprintf(text, textLen, " viarray->v[%lu]", (unsigned long)i);
+        snprintf(text, textLen, " viarray->v[%zu]", i);
         grib_iarray_print(text, viarray->v[i]);
     }
     printf("\n");
diff --git a/tools/bufr_compare.c b/tools/bufr_compare.c
index 17300b1bd..e9b38785b 100644
--- a/tools/bufr_compare.c
+++ b/tools/bufr_compare.c
@@ -559,8 +559,7 @@ int grib_tool_finalise_action(grib_runtime_options* options)
 
     while ((global_handle = codes_bufr_handle_new_from_file(c, options->infile_extra->file, &err))) {
         morein1++;
-        if (global_handle)
-            grib_handle_delete(global_handle);
+        grib_handle_delete(global_handle);
     }
 
     error += morein1 + morein2;
@@ -889,7 +888,7 @@ static int compare_values(grib_runtime_options* options, grib_handle* handle1, g
 
                 if (err1 == GRIB_SUCCESS && err2 == GRIB_SUCCESS && len1 != len2) {
                     printInfo(handle1);
-                    printf("Different size for \"%s\"  [%ld]  [%ld]\n", name, (long)len1, (long)len2);
+                    printf("Different size for \"%s\"  [%zu]  [%zu]\n", name, len1, len2);
                     err1 = GRIB_INTERNAL_ERROR;
                     save_error(c, name);
                 }
@@ -907,7 +906,7 @@ static int compare_values(grib_runtime_options* options, grib_handle* handle1, g
                         if (len1 == 1)
                             printf("string [%s]: [%s] != [%s]\n", name, *svals1, *svals2);
                         else
-                            printf("string [%s] %d out of %ld different\n", name, countdiff, (long)len1);
+                            printf("string [%s] %d out of %zu different\n", name, countdiff, len1);
                     }
                 }
                 for (ii = 0; ii < len1; ++ii) grib_context_free(c, svals1[ii]);
@@ -945,7 +944,7 @@ static int compare_values(grib_runtime_options* options, grib_handle* handle1, g
 
             if (err1 == GRIB_SUCCESS && err2 == GRIB_SUCCESS && len1 != len2) {
                 printInfo(handle1);
-                printf("Different size for \"%s\"  [%ld]  [%ld]\n", name, (long)len1, (long)len2);
+                printf("Different size for \"%s\"  [%zu]  [%zu]\n", name, len1, len2);
                 err1 = GRIB_INTERNAL_ERROR;
                 save_error(c, name);
             }
@@ -963,7 +962,7 @@ static int compare_values(grib_runtime_options* options, grib_handle* handle1, g
                     if (len1 == 1)
                         printf("long [%s]: [%ld] != [%ld]\n", name, *lval1, *lval2);
                     else
-                        printf("long [%s] %d out of %ld different\n", name, countdiff, (long)len1);
+                        printf("long [%s] %d out of %zu different\n", name, countdiff, len1);
                 }
             }
 
@@ -1030,7 +1029,7 @@ static int compare_values(grib_runtime_options* options, grib_handle* handle1, g
 
             if (err1 == GRIB_SUCCESS && err2 == GRIB_SUCCESS && len1 != len2) {
                 printInfo(handle1);
-                printf("Different size for \"%s\"  [%ld]  [%ld]\n", name, (long)len1, (long)len2);
+                printf("Different size for \"%s\"  [%zu]  [%zu]\n", name, len1, len2);
                 save_error(c, name);
             }
             if (err1 == GRIB_SUCCESS && err2 == GRIB_SUCCESS && len1 == len2) {
@@ -1074,7 +1073,7 @@ static int compare_values(grib_runtime_options* options, grib_handle* handle1, g
                     printInfo(handle1);
                     save_error(c, name);
                     if (len1 > 1) {
-                        printf("double [%s]: %d out of %ld different\n", name, countdiff, (long)len1);
+                        printf("double [%s]: %d out of %zu different\n", name, countdiff, len1);
                         if (dval1[imaxdiff] != GRIB_MISSING_DOUBLE && dval2[imaxdiff] != GRIB_MISSING_DOUBLE) {
                             if (compareAbsolute)
                                 printf(" max");
diff --git a/tools/codes_split_file.c b/tools/codes_split_file.c
index 6328a13d1..8896053c1 100644
--- a/tools/codes_split_file.c
+++ b/tools/codes_split_file.c
@@ -84,7 +84,7 @@ static int split_file(FILE* in, const char* filename, const int nchunks, unsigne
             msg_size += size;
             if (read_size > chunk_size && msg_size < insize) {
                 if (verbose)
-                    printf("Wrote output file %s (%lu msgs)\n", ofilename, (unsigned long)num_msg);
+                    printf("Wrote output file %s (%zu msgs)\n", ofilename, num_msg);
                 fclose(out);
                 i++;
                 /* Start writing to the next file */
@@ -103,7 +103,7 @@ static int split_file(FILE* in, const char* filename, const int nchunks, unsigne
         }
     }
     if (verbose)
-        printf("Wrote output file %s (%lu msgs)\n", ofilename, (unsigned long)num_msg - 1);
+        printf("Wrote output file %s (%zu msgs)\n", ofilename, num_msg - 1);
     fclose(out);
     free(ofilename);
 
diff --git a/tools/grib_compare.c b/tools/grib_compare.c
index 19eede597..b2c18e8fd 100644
--- a/tools/grib_compare.c
+++ b/tools/grib_compare.c
@@ -840,7 +840,7 @@ static int compare_values(grib_runtime_options* options, grib_handle* h1, grib_h
 
             if (err1 == GRIB_SUCCESS && err2 == GRIB_SUCCESS && len1 != len2) {
                 printInfo(h1);
-                printf("Different size for \"%s\"  [%ld]  [%ld]\n", name, (long)len1, (long)len2);
+                printf("Different size for \"%s\"  [%zu]  [%zu]\n", name, len1, len2);
                 save_error(c, name);
             }
             if (err1 == GRIB_SUCCESS && err2 == GRIB_SUCCESS && len1 == len2) {
@@ -865,7 +865,7 @@ static int compare_values(grib_runtime_options* options, grib_handle* h1, grib_h
                         printf("\n");
                     }
                     else {
-                        printf("long [%s] %d out of %ld different\n", name, countdiff, (long)len1);
+                        printf("long [%s] %d out of %zu different\n", name, countdiff, len1);
                     }
                 }
             }
@@ -962,7 +962,7 @@ static int compare_values(grib_runtime_options* options, grib_handle* h1, grib_h
 
             if (err1 == GRIB_SUCCESS && err2 == GRIB_SUCCESS && len1 != len2) {
                 printInfo(h1);
-                printf("Different size for \"%s\"  [%ld]  [%ld]\n", name, (long)len1, (long)len2);
+                printf("Different size for \"%s\"  [%zu]  [%zu]\n", name, len1, len2);
                 save_error(c, name);
             }
             if (err1 == GRIB_SUCCESS && err2 == GRIB_SUCCESS && len1 == len2) {
@@ -1012,7 +1012,7 @@ static int compare_values(grib_runtime_options* options, grib_handle* h1, grib_h
                     printInfo(h1);
                     save_error(c, name);
                     if (len1 > 1) {
-                        printf("double [%s]: %d out of %ld different\n", name, countdiff, (long)len1);
+                        printf("double [%s]: %d out of %zu different\n", name, countdiff, len1);
                         if (compareAbsolute)
                             printf(" max");
                         printf(" absolute diff. = %.16e,", fabs(dval1[imaxdiff] - dval2[imaxdiff]));
diff --git a/tools/gts_compare.c b/tools/gts_compare.c
index 96edd4562..9064c51b6 100644
--- a/tools/gts_compare.c
+++ b/tools/gts_compare.c
@@ -332,8 +332,7 @@ int grib_tool_new_handle_action(grib_runtime_options* options, grib_handle* h)
 
         if (!global_handle || err != GRIB_SUCCESS) {
             morein1++;
-            if (global_handle)
-                grib_handle_delete(global_handle);
+            grib_handle_delete(global_handle);
             return 0;
         }