diff --git a/third_party/libmaxminddb/maxminddb.c b/third_party/libmaxminddb/maxminddb.c
index fc110e3d..c08b35ba 100644
--- a/third_party/libmaxminddb/maxminddb.c
+++ b/third_party/libmaxminddb/maxminddb.c
@@ -3,6 +3,7 @@
 #endif
 #include "maxminddb.h"
 #include "maxminddb-compat-util.h"
+#include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
@@ -19,7 +20,6 @@
 #include <unistd.h>
 #endif
 
-
 #define MMDB_DATA_SECTION_SEPARATOR (16)
 
 #ifdef MMDB_DEBUG
@@ -118,6 +118,7 @@ typedef struct record_info_s {
 
 /* *INDENT-OFF* */
 /* --prototypes automatically generated by dev-bin/regen-prototypes.pl - don't remove this comment */
+LOCAL int map_file(MMDB_s *const mmdb);
 LOCAL const uint8_t *find_metadata(const uint8_t *file_content,
                                    ssize_t file_size, uint32_t *metadata_size);
 LOCAL int read_metadata(MMDB_s *mmdb);
@@ -194,6 +195,8 @@ LOCAL char *bytes_to_hex(uint8_t *bytes, uint32_t size);
 
 int MMDB_open(const char *const filename, uint32_t flags, MMDB_s *const mmdb)
 {
+    int status = MMDB_SUCCESS;
+
     mmdb->file_content = NULL;
     mmdb->data_section = NULL;
     mmdb->metadata.database_type = NULL;
@@ -202,85 +205,17 @@ int MMDB_open(const char *const filename, uint32_t flags, MMDB_s *const mmdb)
 
     mmdb->filename = mmdb_strdup(filename);
     if (NULL == mmdb->filename) {
-        free_mmdb_struct(mmdb);
-        return MMDB_OUT_OF_MEMORY_ERROR;
+        status = MMDB_OUT_OF_MEMORY_ERROR;
+        goto cleanup;
     }
 
-    ssize_t size;
-#ifdef _WIN32
-    HANDLE fd = CreateFileA(filename, GENERIC_READ, FILE_SHARE_READ, NULL,
-                            OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
-    if (fd == INVALID_HANDLE_VALUE) {
-        free_mmdb_struct(mmdb);
-        return MMDB_FILE_OPEN_ERROR;
-    }
-    size = GetFileSize(fd, NULL);
-    if (size == INVALID_FILE_SIZE) {
-        free_mmdb_struct(mmdb);
-        CloseHandle(fd);
-        return MMDB_FILE_OPEN_ERROR;
-    }
-#else
-    int fd = open(filename, O_RDONLY);
-    if (fd < 0) {
-        free_mmdb_struct(mmdb);
-        return MMDB_FILE_OPEN_ERROR;
-    }
-
-    struct stat s;
-    if (fstat(fd, &s) ) {
-        free_mmdb_struct(mmdb);
-        close(fd);
-        return MMDB_FILE_OPEN_ERROR;
-    }
-    size = s.st_size;
-#endif
-
     if ((flags & MMDB_MODE_MASK) == 0) {
         flags |= MMDB_MODE_MMAP;
     }
     mmdb->flags = flags;
-    mmdb->file_size = size;
 
-#ifdef _WIN32
-    HANDLE mmh = CreateFileMappingA(fd, NULL, PAGE_READONLY, 0, size, NULL);
-    uint8_t *file_content =
-        (uint8_t *)MapViewOfFile(mmh, FILE_MAP_READ, 0, 0, 0);
-    CloseHandle(fd);
-    if (file_content == NULL) {
-        CloseHandle(mmh);
-        free_mmdb_struct(mmdb);
-        return MMDB_IO_ERROR;
-    }
-#else
-    uint8_t *file_content =
-        (uint8_t *)mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
-    close(fd);
-    if (MAP_FAILED == file_content) {
-        free_mmdb_struct(mmdb);
-        return MMDB_IO_ERROR;
-    }
-#endif
-
-    uint32_t metadata_size = 0;
-    const uint8_t *metadata = find_metadata(file_content, size, &metadata_size);
-    if (NULL == metadata) {
-        free_mmdb_struct(mmdb);
-        return MMDB_INVALID_METADATA_ERROR;
-    }
-
-    mmdb->metadata_section = metadata;
-    mmdb->metadata_section_size = metadata_size;
-
-    int status = read_metadata(mmdb);
-    if (MMDB_SUCCESS != status) {
-        free_mmdb_struct(mmdb);
-        return status;
-    }
-
-    if (mmdb->metadata.binary_format_major_version != 2) {
-        free_mmdb_struct(mmdb);
-        return MMDB_UNKNOWN_DATABASE_FORMAT_ERROR;
+    if (MMDB_SUCCESS != (status = map_file(mmdb)) ) {
+        goto cleanup;
     }
 
 #ifdef _WIN32
@@ -288,17 +223,117 @@ int MMDB_open(const char *const filename, uint32_t flags, MMDB_s *const mmdb)
     WSAStartup(MAKEWORD(2, 2), &wsa);
 #endif
 
+    uint32_t metadata_size = 0;
+    const uint8_t *metadata = find_metadata(mmdb->file_content, mmdb->file_size,
+                                            &metadata_size);
+    if (NULL == metadata) {
+        status = MMDB_INVALID_METADATA_ERROR;
+        goto cleanup;
+    }
+
+    mmdb->metadata_section = metadata;
+    mmdb->metadata_section_size = metadata_size;
+
+    status = read_metadata(mmdb);
+    if (MMDB_SUCCESS != status) {
+        goto cleanup;
+    }
+
+    if (mmdb->metadata.binary_format_major_version != 2) {
+        status = MMDB_UNKNOWN_DATABASE_FORMAT_ERROR;
+        goto cleanup;
+    }
+
     uint32_t search_tree_size = mmdb->metadata.node_count *
                                 mmdb->full_record_byte_size;
 
-    mmdb->file_content = file_content;
-    mmdb->data_section = file_content + search_tree_size;
+    mmdb->data_section = mmdb->file_content + search_tree_size;
     mmdb->data_section_size = mmdb->file_size - search_tree_size;
     mmdb->metadata_section = metadata;
     mmdb->ipv4_start_node.node_value = 0;
     mmdb->ipv4_start_node.netmask = 0;
 
-    return MMDB_SUCCESS;
+ cleanup:
+    if (MMDB_SUCCESS != status) {
+        int saved_errno = errno;
+        free_mmdb_struct(mmdb);
+        errno = saved_errno;
+    }
+    return status;
+}
+
+LOCAL int map_file(MMDB_s *const mmdb)
+{
+    ssize_t size;
+    int status = MMDB_SUCCESS;
+#ifdef _WIN32
+    HANDLE fd = INVALID_HANDLE_VALUE;
+    HANDLE mmh = NULL;
+
+    fd = CreateFileA(mmdb->filename, GENERIC_READ, FILE_SHARE_READ, NULL,
+                     OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+    if (fd == INVALID_HANDLE_VALUE) {
+        status = MMDB_FILE_OPEN_ERROR;
+        goto cleanup;
+    }
+    size = GetFileSize(fd, NULL);
+    if (size == INVALID_FILE_SIZE) {
+        status = MMDB_FILE_OPEN_ERROR;
+        goto cleanup;
+    }
+    mmh = CreateFileMappingA(fd, NULL, PAGE_READONLY, 0, size, NULL);
+    if (NULL == mmh) {  /* Microsoft documentation for CreateFileMapping indicates this returns NULL not INVALID_HANDLE_VALUE on error */
+        status = MMDB_IO_ERROR;
+        goto cleanup;
+    }
+    uint8_t *file_content =
+        (uint8_t *)MapViewOfFile(mmh, FILE_MAP_READ, 0, 0, 0);
+    if (file_content == NULL) {
+        status = MMDB_IO_ERROR;
+        goto cleanup;
+    }
+#else
+    int fd = open(mmdb->filename, O_RDONLY);
+    struct stat s;
+    if (fd < 0 || fstat(fd, &s)) {
+        status = MMDB_FILE_OPEN_ERROR;
+        goto cleanup;
+    }
+
+    size = s.st_size;
+
+    uint8_t *file_content =
+        (uint8_t *)mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
+    if (MAP_FAILED == file_content) {
+        if (ENOMEM == errno) {
+            status = MMDB_OUT_OF_MEMORY_ERROR;
+        } else {
+            status = MMDB_IO_ERROR;
+        }
+        goto cleanup;
+    }
+#endif
+
+    mmdb->file_size = size;
+    mmdb->file_content = file_content;
+
+ cleanup:;
+    int saved_errno = errno;
+#ifdef _WIN32
+    if (INVALID_HANDLE_VALUE != fd) {
+        CloseHandle(fd);
+    }
+    if (NULL != mmh) {
+        CloseHandle(mmh);
+    }
+#else
+    if (fd >= 0) {
+        close(fd);
+    }
+#endif
+    errno = saved_errno;
+
+    return status;
 }
 
 LOCAL const uint8_t *find_metadata(const uint8_t *file_content,
@@ -309,7 +344,7 @@ LOCAL const uint8_t *find_metadata(const uint8_t *file_content,
                        file_size;
 
     uint8_t *search_area = (uint8_t *)(file_content + (file_size - max_size));
-    uint8_t *tmp = search_area;
+    uint8_t *tmp;
     do {
         tmp = mmdb_memmem(search_area, max_size,
                           METADATA_MARKER, strlen(METADATA_MARKER));
@@ -535,6 +570,11 @@ LOCAL int populate_description_metadata(MMDB_s *mmdb, MMDB_s *metadata_db,
 
     uint32_t map_size = member->entry_data.data_size;
     mmdb->metadata.description.count = 0;
+    if (0 == map_size) {
+        mmdb->metadata.description.descriptions = NULL;
+        goto cleanup;
+    }
+
     mmdb->metadata.description.descriptions =
         malloc(map_size * sizeof(MMDB_description_s *));
     if (NULL == mmdb->metadata.description.descriptions) {
@@ -581,6 +621,7 @@ LOCAL int populate_description_metadata(MMDB_s *mmdb, MMDB_s *metadata_db,
         }
     }
 
+ cleanup:
     MMDB_free_entry_data_list(first_member);
 
     return MMDB_SUCCESS;
@@ -604,23 +645,22 @@ MMDB_lookup_result_s MMDB_lookup_string(MMDB_s *const mmdb,
     *gai_error = resolve_any_address(ipstr, &addresses);
 
     if (*gai_error) {
-        if (NULL != addresses) {
-            freeaddrinfo(addresses);
-        }
-        return result;
+        goto cleanup;
     }
 
     if (mmdb->metadata.ip_version == 4
         && addresses->ai_addr->sa_family == AF_INET6) {
 
         *mmdb_error = MMDB_IPV6_LOOKUP_IN_IPV4_DATABASE_ERROR;
-        freeaddrinfo(addresses);
-        return result;
+        goto cleanup;
     }
 
     result = MMDB_lookup_sockaddr(mmdb, addresses->ai_addr, mmdb_error);
 
-    freeaddrinfo(addresses);
+ cleanup:
+    if (NULL != addresses) {
+        freeaddrinfo(addresses);
+    }
 
     return result;
 }
@@ -783,6 +823,8 @@ LOCAL record_info_s record_info_for_database(MMDB_s *mmdb)
         record_info.left_record_getter = &get_uint32;
         record_info.right_record_getter = &get_uint32;
         record_info.right_record_offset = 4;
+    } else {
+        assert(false);
     }
 
     return record_info;
diff --git a/third_party/libmaxminddb/maxminddb.h b/third_party/libmaxminddb/maxminddb.h
index de76c473..40f15a95 100644
--- a/third_party/libmaxminddb/maxminddb.h
+++ b/third_party/libmaxminddb/maxminddb.h
@@ -36,7 +36,7 @@ typedef ADDRESS_FAMILY sa_family_t;
 #endif
 
 /* libmaxminddb package version from configure */
-#define PACKAGE_VERSION "1.0.4"
+#define PACKAGE_VERSION "1.1.0"
 
 #define MMDB_DATA_TYPE_EXTENDED (0)
 #define MMDB_DATA_TYPE_POINTER (1)