diff --git a/src/address_dictionary.h b/src/address_dictionary.h
index c174b002..ccd99b05 100644
--- a/src/address_dictionary.h
+++ b/src/address_dictionary.h
@@ -21,7 +21,8 @@
 
 #define ALL_LANGUAGES "all"
 
-#define DEFAULT_ADDRESS_EXPANSION_PATH LIBPOSTAL_DATA_DIR PATH_SEPARATOR "address_expansions" PATH_SEPARATOR "address_dictionary.dat"
+#define ADDRESS_DICTIONARY_DATA_FILE "address_dictionary.dat"
+#define DEFAULT_ADDRESS_EXPANSION_PATH LIBPOSTAL_DATA_DIR PATH_SEPARATOR LIBPOSTAL_ADDRESS_EXPANSIONS_SUBDIR PATH_SEPARATOR ADDRESS_DICTIONARY_DATA_FILE
 
 #define NULL_CANONICAL_INDEX -1
 
diff --git a/src/file_utils.c b/src/file_utils.c
index 1747bbd8..4a320d83 100644
--- a/src/file_utils.c
+++ b/src/file_utils.c
@@ -36,6 +36,21 @@ bool is_relative_path(struct dirent *ent) {
     return strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0;
 }
 
+char *path_vjoin(int n, va_list args) {
+    char_array *path = char_array_new();
+    if (path == NULL) return NULL;
+    char_array_add_vjoined(path, PATH_SEPARATOR, true, n, args);
+    return char_array_to_string(path);
+}
+
+char *path_join(int n, ...) {
+    va_list args;
+    va_start(args, n);
+    char *path = path_vjoin(n, args);
+    va_end(args);
+    return path;
+}
+
 inline uint64_t file_deserialize_uint64(unsigned char *buf) {
     return ((uint64_t)buf[0] << 56) | 
            ((uint64_t)buf[1] << 48) |
diff --git a/src/file_utils.h b/src/file_utils.h
index 13fa1e39..b6648500 100644
--- a/src/file_utils.h
+++ b/src/file_utils.h
@@ -9,6 +9,7 @@
 #include <sys/types.h>
 
 #include "libpostal_config.h"
+#include "string_utils.h"
 
 #ifdef HAVE_DIRENT_H
 #include <dirent.h>
@@ -55,6 +56,9 @@ char *file_getline(FILE * f);
 
 bool is_relative_path(struct dirent *ent);
 
+char *path_join(int n, ...);
+char *path_vjoin(int n, va_list args);
+
 uint64_t file_deserialize_uint64(unsigned char *buf);
 bool file_read_uint64(FILE *file, uint64_t *value);
 bool file_write_uint64(FILE *file, uint64_t value);
diff --git a/src/libpostal.c b/src/libpostal.c
index 978f9b70..06401146 100644
--- a/src/libpostal.c
+++ b/src/libpostal.c
@@ -1054,45 +1054,106 @@ address_parser_response_t *parse_address(char *address, address_parser_options_t
     return parsed;
 }
 
+bool libpostal_setup_datadir(char *datadir) {
+    char *transliteration_path = NULL;
+    char *numex_path = NULL;
+    char *address_dictionary_path = NULL;
+
+    if (datadir != NULL) {
+        transliteration_path = path_join(3, datadir, LIBPOSTAL_TRANSLITERATION_SUBDIR, TRANSLITERATION_DATA_FILE);
+        numex_path = path_join(3, datadir, LIBPOSTAL_NUMEX_SUBDIR, NUMEX_DATA_FILE);
+        address_dictionary_path = path_join(3, datadir, LIBPOSTAL_ADDRESS_EXPANSIONS_SUBDIR, ADDRESS_DICTIONARY_DATA_FILE);
+    }
+
+    if (!transliteration_module_setup(transliteration_path)) {
+        log_error("Error loading transliteration module, dir=%s\n", transliteration_path);
+        return false;
+    }
+
+    if (!numex_module_setup(numex_path)) {
+        log_error("Error loading numex module, dir=%s\n", numex_path);
+        return false;
+    }
+
+    if (!address_dictionary_module_setup(address_dictionary_path)) {
+        log_error("Error loading dictionary module, dir=%s\n", address_dictionary_path);
+        return false;
+    }
+
+    if (transliteration_path != NULL) {
+        free(transliteration_path);
+    }
+
+    if (numex_path != NULL) {
+        free(numex_path);
+    }
+
+    if (address_dictionary_path != NULL) {
+        free(address_dictionary_path);
+    }
+
+    return true;
+}
+
 bool libpostal_setup(void) {
-    if (!transliteration_module_setup(NULL)) {
-        log_error("Error loading transliteration module, LIBPOSTAL_DATA_DIR=%s\n", LIBPOSTAL_DATA_DIR);
+    return libpostal_setup_datadir(NULL);
+}
+
+bool libpostal_setup_language_classifier_datadir(char *datadir) {
+    char *language_classifier_dir = NULL;
+
+    if (datadir != NULL) {
+        language_classifier_dir = path_join(2, datadir, LIBPOSTAL_LANGUAGE_CLASSIFIER_SUBDIR);
+    }
+
+    if (!language_classifier_module_setup(language_classifier_dir)) {
+        log_error("Error loading language classifier, dir=%s\n", language_classifier_dir);
         return false;
     }
 
-    if (!numex_module_setup(NULL)) {
-        log_error("Error loading numex module, LIBPOSTAL_DATA_DIR=%s\n", LIBPOSTAL_DATA_DIR);
-        return false;
-    }
-
-    if (!address_dictionary_module_setup(NULL)) {
-        log_error("Error loading dictionary module, LIBPOSTAL_DATA_DIR=%s\n", LIBPOSTAL_DATA_DIR);
-        return false;
+    if (language_classifier_dir != NULL) {
+        free(language_classifier_dir);
     }
 
     return true;
 }
 
 bool libpostal_setup_language_classifier(void) {
-    if (!language_classifier_module_setup(NULL)) {
-        log_error("Error loading language classifier, LIBPOSTAL_DATA_DIR=%s\n", LIBPOSTAL_DATA_DIR);
+    return libpostal_setup_language_classifier_datadir(NULL);
+}
+
+bool libpostal_setup_parser_datadir(char *datadir) {
+    char *parser_dir = NULL;
+    char *geodb_dir = NULL;
+
+    if (datadir != NULL) {
+        parser_dir = path_join(2, datadir, LIBPOSTAL_ADDRESS_PARSER_SUBDIR);
+        geodb_dir = path_join(2, datadir, LIBPOSTAL_GEODB_SUBDIR);
+    }
+
+    if (!geodb_module_setup(geodb_dir)) {
+        log_error("Error loading geodb module, dir=%s\n", geodb_dir);
         return false;
     }
+
+    if (!address_parser_module_setup(parser_dir)) {
+        log_error("Error loading address parser module, dir=%s\n", parser_dir);
+        return false;
+    }
+
+    if (parser_dir != NULL) {
+        free(parser_dir);
+    }
+
+    if (geodb_dir != NULL) {
+        free(geodb_dir);
+    }
+
     return true;
 }
 
 bool libpostal_setup_parser(void) {
-    if (!geodb_module_setup(NULL)) {
-        log_error("Error loading geodb module, LIBPOSTAL_DATA_DIR=%s\n", LIBPOSTAL_DATA_DIR);
-        return false;
-    }
-
-    if (!address_parser_module_setup(NULL)) {
-        log_error("Error loading address parser module, LIBPOSTAL_DATA_DIR=%s\n", LIBPOSTAL_DATA_DIR);
-        return false;
-    }
-
-    return true;
+    return libpostal_setup_parser_datadir(NULL);
 }
 
 void libpostal_teardown(void) {
diff --git a/src/libpostal.h b/src/libpostal.h
index 30646e59..178d6225 100644
--- a/src/libpostal.h
+++ b/src/libpostal.h
@@ -92,12 +92,15 @@ address_parser_response_t *parse_address(char *address, address_parser_options_t
 // Setup/teardown methods
 
 bool libpostal_setup(void);
+bool libpostal_setup_datadir(char *datadir);
 void libpostal_teardown(void);
 
 bool libpostal_setup_parser(void);
+bool libpostal_setup_parser_datadir(char *datadir);
 void libpostal_teardown_parser(void);
 
 bool libpostal_setup_language_classifier(void);
+bool libpostal_setup_language_classifier_datadir(char *datadir);
 void libpostal_teardown_language_classifier(void);
 
 #ifdef __cplusplus
diff --git a/src/libpostal_config.h b/src/libpostal_config.h
index 6b07a9b8..4d935665 100644
--- a/src/libpostal_config.h
+++ b/src/libpostal_config.h
@@ -12,12 +12,20 @@
 #error LIBPOSTAL_DATA_DIR not defined!
 #endif
 
-#define LIBPOSTAL_ADDRESS_PARSER_DIR LIBPOSTAL_DATA_DIR PATH_SEPARATOR "address_parser"
-#define LIBPOSTAL_DICTIONARIES_DIR LIBPOSTAL_DATA_DIR PATH_SEPARATOR "dictionaries"
-#define LIBPOSTAL_GEONAMES_DIR LIBPOSTAL_DATA_DIR PATH_SEPARATOR "geonames"
-#define LIBPOSTAL_GEODB_DIR LIBPOSTAL_DATA_DIR PATH_SEPARATOR "geodb"
-#define LIBPOSTAL_LANGUAGE_CLASSIFIER_DIR LIBPOSTAL_DATA_DIR PATH_SEPARATOR "language_classifier"
-#define LIBPOSTAL_TRANSLITERATION_DIR LIBPOSTAL_DATA_DIR PATH_SEPARATOR "transliteration"
+#define LIBPOSTAL_ADDRESS_PARSER_SUBDIR "address_parser"
+#define LIBPOSTAL_ADDRESS_PARSER_DIR LIBPOSTAL_DATA_DIR PATH_SEPARATOR LIBPOSTAL_ADDRESS_PARSER_SUBDIR
+#define LIBPOSTAL_ADDRESS_EXPANSIONS_SUBDIR "address_expansions"
+#define LIBPOSTAL_ADDRESS_EXPANSIONS_DIR LIBPOSTAL_DATA_DIR PATH_SEPARATOR LIBPOSTAL_ADDRESS_EXPANSIONS_SUBDIR
+#define LIBPOSTAL_GEONAMES_SUBDIR "geonames"
+#define LIBPOSTAL_GEONAMES_DIR LIBPOSTAL_DATA_DIR PATH_SEPARATOR LIBPOSTAL_GEONAMES_SUBDIR
+#define LIBPOSTAL_GEODB_SUBDIR "geodb"
+#define LIBPOSTAL_GEODB_DIR LIBPOSTAL_DATA_DIR PATH_SEPARATOR LIBPOSTAL_GEODB_SUBDIR
+#define LIBPOSTAL_LANGUAGE_CLASSIFIER_SUBDIR "language_classifier"
+#define LIBPOSTAL_LANGUAGE_CLASSIFIER_DIR LIBPOSTAL_DATA_DIR PATH_SEPARATOR LIBPOSTAL_LANGUAGE_CLASSIFIER_SUBDIR
+#define LIBPOSTAL_NUMEX_SUBDIR "numex"
+#define LIBPOSTAL_NUMEX_DIR LIBPOSTAL_DATA_DIR PATH_SEPARATOR LIBPOSTAL_NUMEX_SUBDIR
+#define LIBPOSTAL_TRANSLITERATION_SUBDIR "transliteration"
+#define LIBPOSTAL_TRANSLITERATION_DIR LIBPOSTAL_DATA_DIR PATH_SEPARATOR LIBPOSTAL_TRANSLITERATION_SUBDIR
 
 #define GEODB_BLOOM_FILTER_SIZE 100000000
 #define GEODB_BLOOM_FILTER_ERROR 0.001
diff --git a/src/numex.h b/src/numex.h
index 421435ec..9d8d9f4a 100644
--- a/src/numex.h
+++ b/src/numex.h
@@ -20,7 +20,8 @@
 #include "trie.h"
 #include "trie_search.h"
 
-#define DEFAULT_NUMEX_PATH LIBPOSTAL_DATA_DIR PATH_SEPARATOR "numex" PATH_SEPARATOR "numex.dat"
+#define NUMEX_DATA_FILE "numex.dat"
+#define DEFAULT_NUMEX_PATH LIBPOSTAL_DATA_DIR PATH_SEPARATOR "numex" PATH_SEPARATOR NUMEX_DATA_FILE
 
 #define LATIN_LANGUAGE_CODE "la"
 
diff --git a/src/transliterate.h b/src/transliterate.h
index 885f9989..79230a56 100644
--- a/src/transliterate.h
+++ b/src/transliterate.h
@@ -15,7 +15,8 @@
 
 #define LATIN_ASCII "latin-ascii"
 
-#define DEFAULT_TRANSLITERATION_PATH LIBPOSTAL_TRANSLITERATION_DIR PATH_SEPARATOR "transliteration.dat"
+#define TRANSLITERATION_DATA_FILE "transliteration.dat"
+#define DEFAULT_TRANSLITERATION_PATH LIBPOSTAL_TRANSLITERATION_DIR PATH_SEPARATOR TRANSLITERATION_DATA_FILE
 
 #define MAX_TRANS_NAME_LEN 100