diff --git a/libclamav/bytecode_api.c b/libclamav/bytecode_api.c
index 9d136387a3..5a77fb0aa1 100644
--- a/libclamav/bytecode_api.c
+++ b/libclamav/bytecode_api.c
@@ -472,7 +472,7 @@ uint8_t *cli_bcapi_malloc(struct cli_bc_ctx *ctx, uint32_t size)
     }
 
     if (0 == size || size > CLI_MAX_ALLOCATION) {
-        cli_warnmsg("cli_bcapi_malloc(): File or section is too large to scan (%u bytes). For your safety, ClamAV limits how much memory an operation can allocate to %d bytes\n",
+        cli_warnmsg("cli_bcapi_malloc(): File or section is too large to scan (" STDu32 " bytes). For your safety, ClamAV limits how much memory an operation can allocate to %d bytes\n",
                     size, CLI_MAX_ALLOCATION);
         v = NULL;
     } else {
diff --git a/libclamav/hashtab.c b/libclamav/hashtab.c
index fdc2d6cbf6..75213217eb 100644
--- a/libclamav/hashtab.c
+++ b/libclamav/hashtab.c
@@ -889,7 +889,7 @@ cl_error_t cli_map_addkey(struct cli_map *m, const void *key, int32_t keysize)
     if (m->valuesize) {
         void *v;
 
-        v = cli_max_realloc(m->u.sized_values, n * m->valuesize);
+        v = cli_max_realloc(m->u.sized_values, (size_t)n * (size_t)m->valuesize);
         if (!v) {
             return CL_EMEM;
         }
diff --git a/libclamav/nsis/bzlib.c b/libclamav/nsis/bzlib.c
index 0e14088f3b..b67d97a83b 100644
--- a/libclamav/nsis/bzlib.c
+++ b/libclamav/nsis/bzlib.c
@@ -990,7 +990,7 @@ int bz_config_ok ( void )
 static
 void* default_bzalloc ( void* opaque, Int32 items, Int32 size )
 {
-    void* v = cli_max_malloc ( items * size );
+    void* v = cli_max_malloc ( (size_t)items * (size_t)size );
     UNUSEDPARAM(opaque);
     return v;
 }
diff --git a/libclamav/pe_icons.c b/libclamav/pe_icons.c
index 5feb7b97cd..023b346a6b 100644
--- a/libclamav/pe_icons.c
+++ b/libclamav/pe_icons.c
@@ -901,7 +901,7 @@ static int getmetrics(unsigned int side, unsigned int *imagedata, struct icomtr
     unsigned int edge_avg[6], edge_x[6] = {0, 0, 0, 0, 0, 0}, edge_y[6] = {0, 0, 0, 0, 0, 0}, noedge_avg[6], noedge_x[6] = {0, 0, 0, 0, 0, 0}, noedge_y[6] = {0, 0, 0, 0, 0, 0};
     double *sobel;
 
-    if (!(tmp = cli_max_malloc(side * side * 4 * 2))) {
+    if (!(tmp = cli_max_malloc((size_t)side * (size_t)side * 4 * 2))) {
         cli_errmsg("getmetrics: Unable to allocate memory for tmp %u\n", (side * side * 4 * 2));
         return CL_EMEM;
     }
@@ -1067,7 +1067,7 @@ static int getmetrics(unsigned int side, unsigned int *imagedata, struct icomtr
     /* Sobel 1 - gradients */
     i = 0;
 #ifdef USE_FLOATS
-    sobel = cli_max_malloc(side * side * sizeof(double));
+    sobel = cli_max_malloc((size_t)side * (size_t)side * sizeof(double));
     if (!sobel) {
         cli_errmsg("getmetrics: Unable to allocate memory for edge detection %llu\n", (long long unsigned)(side * side * sizeof(double)));
         free(tmp);
@@ -1457,7 +1457,7 @@ static int parseicon(struct ICON_ENV *icon_env, uint32_t rva)
             fmap_unneed_ptr(map, palette, (1 << depth) * sizeof(int));
         return CL_SUCCESS;
     }
-    if (!(imagedata = cli_max_malloc(width * height * sizeof(*imagedata)))) {
+    if (!(imagedata = cli_max_malloc((size_t)width * (size_t)height * sizeof(*imagedata)))) {
         if (palette)
             fmap_unneed_ptr(map, palette, (1 << depth) * sizeof(int));
         return CL_SUCCESS;