diff --git a/src/lib/openjp2/j2k.c b/src/lib/openjp2/j2k.c
index e1901a31..220f4b1e 100644
--- a/src/lib/openjp2/j2k.c
+++ b/src/lib/openjp2/j2k.c
@@ -1677,7 +1677,7 @@ static OPJ_BOOL opj_j2k_check_poc_val(const opj_poc_t *p_pocs,
 
     assert(p_nb_pocs > 0);
 
-    packet_array = (OPJ_UINT32*) opj_calloc(step_l * p_num_layers,
+    packet_array = (OPJ_UINT32*) opj_calloc((size_t)step_l * p_num_layers,
                                             sizeof(OPJ_UINT32));
     if (packet_array == 00) {
         opj_event_msg(p_manager, EVT_ERROR,
diff --git a/src/lib/openjp2/jp2.c b/src/lib/openjp2/jp2.c
index 63a3a1a2..449440b8 100644
--- a/src/lib/openjp2/jp2.c
+++ b/src/lib/openjp2/jp2.c
@@ -1136,9 +1136,9 @@ static OPJ_BOOL opj_jp2_apply_pclr(opj_image_t *image,
     }
 
     max = image->numcomps;
-    for (i = 0; i < max; ++i) {
-        if (old_comps[i].data) {
-            opj_image_data_free(old_comps[i].data);
+    for (j = 0; j < max; ++j) {
+        if (old_comps[j].data) {
+            opj_image_data_free(old_comps[j].data);
         }
     }
 
diff --git a/src/lib/openjp2/mct.c b/src/lib/openjp2/mct.c
index 88c8f409..78058128 100644
--- a/src/lib/openjp2/mct.c
+++ b/src/lib/openjp2/mct.c
@@ -457,7 +457,7 @@ void opj_calculate_norms(OPJ_FLOAT64 * pNorms,
         for (j = 0; j < pNbComps; ++j) {
             lCurrentValue = lMatrix[lIndex];
             lIndex += pNbComps;
-            lNorms[i] += lCurrentValue * lCurrentValue;
+            lNorms[i] += (OPJ_FLOAT64) lCurrentValue * lCurrentValue;
         }
         lNorms[i] = sqrt(lNorms[i]);
     }
diff --git a/src/lib/openjp2/sparse_array.c b/src/lib/openjp2/sparse_array.c
index 73192924..50d1a904 100644
--- a/src/lib/openjp2/sparse_array.c
+++ b/src/lib/openjp2/sparse_array.c
@@ -69,7 +69,7 @@ opj_sparse_array_int32_t* opj_sparse_array_int32_create(OPJ_UINT32 width,
         return NULL;
     }
     sa->data_blocks = (OPJ_INT32**) opj_calloc(sizeof(OPJ_INT32*),
-                      sa->block_count_hor * sa->block_count_ver);
+                      (size_t) sa->block_count_hor * sa->block_count_ver);
     if (sa->data_blocks == NULL) {
         opj_free(sa);
         return NULL;
@@ -235,7 +235,7 @@ static OPJ_BOOL opj_sparse_array_int32_read_or_write(
             } else {
                 if (src_block == NULL) {
                     src_block = (OPJ_INT32*) opj_calloc(1,
-                                                        sa->block_width * sa->block_height * sizeof(OPJ_INT32));
+                                                        (size_t) sa->block_width * sa->block_height * sizeof(OPJ_INT32));
                     if (src_block == NULL) {
                         return OPJ_FALSE;
                     }