diff --git a/epan/dissectors/file-elf.c b/epan/dissectors/file-elf.c
index 744e85116c..685b0a526f 100644
--- a/epan/dissectors/file-elf.c
+++ b/epan/dissectors/file-elf.c
@@ -603,7 +603,7 @@ static const range_string dynamic_tag_rvals[] = {
 typedef struct _segment_info_t {
     guint64        offset;
     guint64        size;
-    const guint8  *name;
+    const char  *name;
 } segment_info_t;
 
 void proto_register_elf(void);
@@ -1094,7 +1094,7 @@ dissect_eh_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *segment_tree,
                                 tvb, offset, 1, machine_encoding);
             offset += 1;
 
-            augmentation_string = tvb_get_const_stringz(tvb, offset, &size);
+            augmentation_string = (const gchar*)tvb_get_const_stringz(tvb, offset, &size);
             proto_tree_add_item(entry_tree, hf_elf_eh_frame_augmentation_string,
                                 tvb, offset, size, machine_encoding);
             offset += size;
@@ -1185,7 +1185,7 @@ dissect_elf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
     guint16          shstrndx;
     guint64          shstrtab_offset;
     guint32          sh_name;
-    const guint8    *section_name;
+    const char      *section_name;
     guint64          length;
     guint64          segment_offset;
     guint64          segment_size;
@@ -1471,7 +1471,7 @@ dissect_elf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
                     tvb_get_ntoh64(tvb, value_guard(length)) : tvb_get_letoh64(tvb, value_guard(length));
         }
 
-        section_name = tvb_get_const_stringz(tvb, value_guard(shstrtab_offset + sh_name), NULL);
+        section_name = (const char *)tvb_get_const_stringz(tvb, value_guard(shstrtab_offset + sh_name), NULL);
 
         if (register_size == REGISTER_64_SIZE && machine_encoding == ENC_BIG_ENDIAN) {
             offset += 4;
@@ -1546,7 +1546,7 @@ dissect_elf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
                     tvb_get_ntoh64(tvb, value_guard(length)) : tvb_get_letoh64(tvb, value_guard(length));
         }
 
-        section_name = tvb_get_const_stringz(tvb, value_guard(shstrtab_offset + sh_name), NULL);
+        section_name = (const char*)tvb_get_const_stringz(tvb, value_guard(shstrtab_offset + sh_name), NULL);
         if (section_name)
             proto_item_append_text(sh_entry_item, ": %s", section_name);
 
diff --git a/epan/dissectors/file-jpeg.c b/epan/dissectors/file-jpeg.c
index 4a2e703a54..56c2e425da 100644
--- a/epan/dissectors/file-jpeg.c
+++ b/epan/dissectors/file-jpeg.c
@@ -520,7 +520,7 @@ process_app0_segment(proto_tree *tree, tvbuff_t *tvb, guint32 len,
 
     proto_tree_add_item(subtree, hf_len, tvb, 2, 2, ENC_BIG_ENDIAN);
 
-    str = tvb_get_stringz_enc(wmem_packet_scope(), tvb, 4, &str_size, ENC_ASCII);
+    str = (char *)tvb_get_stringz_enc(wmem_packet_scope(), tvb, 4, &str_size, ENC_ASCII);
     ti = proto_tree_add_item(subtree, hf_identifier, tvb, 4, str_size, ENC_ASCII|ENC_NA);
     if (strcmp(str, "JFIF") == 0) {
         /* Version */
@@ -599,7 +599,7 @@ process_app1_segment(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, guint3
     proto_tree_add_item(subtree, hf_len, tvb, offset, 2, ENC_BIG_ENDIAN);
     offset += 2;
 
-    str = tvb_get_stringz_enc(wmem_packet_scope(), tvb, offset, &str_size, ENC_ASCII);
+    str = (char*)tvb_get_stringz_enc(wmem_packet_scope(), tvb, offset, &str_size, ENC_ASCII);
     ti = proto_tree_add_item(subtree, hf_identifier, tvb, offset, str_size, ENC_ASCII|ENC_NA);
     offset += str_size;
 
@@ -723,7 +723,7 @@ process_app2_segment(proto_tree *tree, tvbuff_t *tvb, guint32 len,
 
     proto_tree_add_item(subtree, hf_len, tvb, 2, 2, ENC_BIG_ENDIAN);
 
-    str = tvb_get_stringz_enc(wmem_packet_scope(), tvb, 4, &str_size, ENC_ASCII);
+    str = (char*)tvb_get_stringz_enc(wmem_packet_scope(), tvb, 4, &str_size, ENC_ASCII);
     ti = proto_tree_add_item(subtree, hf_identifier, tvb, 4, str_size, ENC_ASCII|ENC_NA);
     if (strcmp(str, "FPXR") == 0) {
         proto_tree_add_item(tree, hf_exif_flashpix_marker, tvb, 0, -1, ENC_NA);
@@ -751,10 +751,10 @@ dissect_jfif(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_
         return 0;
     /* Check identifier field in first App segment is "JFIF", although "Exif" from App1
        can/does appear here too... */
-    if (tvb_memeql(tvb, 6, "Exif", 5) == 0) {
+    if (tvb_memeql(tvb, 6, (const guint8*)"Exif", 5) == 0) {
         show_first_identifier_not_jfif = TRUE;
     }
-    else if (tvb_memeql(tvb, 6, "JFIF", 5)) {
+    else if (tvb_memeql(tvb, 6, (const guint8*)"JFIF", 5)) {
         return 0;
     }
 
diff --git a/epan/dissectors/file-pcapng.c b/epan/dissectors/file-pcapng.c
index 875cf46489..7fcfb1bb18 100644
--- a/epan/dissectors/file-pcapng.c
+++ b/epan/dissectors/file-pcapng.c
@@ -1156,7 +1156,7 @@ static gint dissect_options(proto_tree *tree, packet_info *pinfo,
 
                 proto_tree_add_item(option_tree, hf_pcapng_option_data_packet_drop_count, tvb, offset, 8, encoding);
                 value.u64 = tvb_get_guint64(tvb, offset, encoding);
-                str = wmem_strdup_printf(wmem_packet_scope(), "%"G_GUINT64_FORMAT, value.u64);
+                str = (const guint8*)wmem_strdup_printf(wmem_packet_scope(), "%"G_GUINT64_FORMAT, value.u64);
                 offset += 8;
 
                 break;
@@ -1165,7 +1165,7 @@ static gint dissect_options(proto_tree *tree, packet_info *pinfo,
                 value.u32 = tvb_get_guint32(tvb, offset, encoding);
                 offset += option_length;
 
-                str = wmem_strdup_printf(wmem_packet_scope(), "%u", value.u32);
+                str = (const guint8*)wmem_strdup_printf(wmem_packet_scope(), "%u", value.u32);
 
                 break;
             case 32770: /* Darwin Service Type */
@@ -1173,7 +1173,7 @@ static gint dissect_options(proto_tree *tree, packet_info *pinfo,
                 value.u32 = tvb_get_guint32(tvb, offset, encoding);
                 offset += option_length;
 
-                str = wmem_strdup_printf(wmem_packet_scope(), "%s", val_to_str_const(value.u32, option_code_darwin_svc_class_vals, "Unknown"));
+                str = (const guint8*)wmem_strdup_printf(wmem_packet_scope(), "%s", val_to_str_const(value.u32, option_code_darwin_svc_class_vals, "Unknown"));
 
                 break;
             case 32771: /* Darwin Effective DPEB ID */
@@ -1181,7 +1181,7 @@ static gint dissect_options(proto_tree *tree, packet_info *pinfo,
                 value.u32 = tvb_get_guint32(tvb, offset, encoding);
                 offset += option_length;
 
-                str = wmem_strdup_printf(wmem_packet_scope(), "%u", value.u32);
+                str = (const guint8*)wmem_strdup_printf(wmem_packet_scope(), "%u", value.u32);
 
                 break;
             default: