diff --git a/tests/.gitignore b/tests/.gitignore
index 1f3e1d8..d84037d 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -1,5 +1,7 @@
+.DS_Store
+.vscode
 *.dSYM
-a.out
+*.out
 *.test
 *.o
 *.svg
@@ -8,6 +10,10 @@ a.out
 *.cov.html
 *.out.js
 *.out.wasm
+*.c.wasm
+*.c.test
+*.c.worker.js
+relations.h
 libgeos
 fuzz-*
 slow-*
diff --git a/tests/genrelations.sh b/tests/genrelations.sh
new file mode 100755
index 0000000..f239e85
--- /dev/null
+++ b/tests/genrelations.sh
@@ -0,0 +1,39 @@
+#!/bin/bash
+
+set -e
+cd $(dirname "${BASH_SOURCE[0]}")
+
+compfile() {
+    hexdump -v -e '16/1 "_x%02X" "\n"' $1 | \
+        sed 's/_/\\/g; s/\\x  //g; s/.*/    "&"/'
+    echo ";"
+}
+
+compheader() {
+    echo "// Auto generated file, DO NOT EDIT"
+    for file in relations/*.jsonc
+    do
+        filename=$(basename $file)
+        filename="${filename%.*}_jsonc"
+        echo "static const char $filename[] ="
+        compfile $file
+    done
+    echo "    
+struct relation {
+    const char *name;
+    const char *data;
+};
+
+static struct relation relations[] = {"
+    for file in relations/*.jsonc
+    do
+        filename=$(basename $file)
+        filename="${filename%.*}_jsonc"
+        printf "    { \"%s\", %s },\n" $(basename $file) $filename
+    done
+
+    echo "};"
+}
+
+compheader > relations.h
+
diff --git a/tests/run.sh b/tests/run.sh
index 4b9a6bb..ae5f081 100755
--- a/tests/run.sh
+++ b/tests/run.sh
@@ -13,8 +13,8 @@ finish() {
     rm -fr *.profraw
     rm -fr *.dSYM
     rm -fr *.profdata
-    rm -fr *.out.wasm
-    rm -fr *.out.js
+    rm -fr *.wasm
+    rm -fr *.js
     if [[ "$OK" != "1" ]]; then
         echo "FAIL"
     fi
@@ -91,6 +91,15 @@ if [[ "$1" != "bench" ]]; then
 else
     CFLAGS=${CFLAGS:-"-O3"}
 fi
+if [[ "$CC" == "emcc" ]]; then
+    # Running emscripten
+    CFLAGS="$CFLAGS -sASYNCIFY -sALLOW_MEMORY_GROWTH -sSTACK_SIZE=5MB"
+    CFLAGS="$CFLAGS -Wno-limited-postlink-optimizations"
+    CFLAGS="$CFLAGS -Wno-unused-command-line-argument"
+    CFLAGS="$CFLAGS -Wno-pthreads-mem-growth"
+    CFLAGS="$CFLAGS -O3" # needs optimizations for test_wkb_max_depth test
+fi
+
 CC=${CC:-cc}
 echo "CC: $CC"
 echo "CFLAGS: $CFLAGS"
@@ -106,6 +115,8 @@ if [[ "$NOSANS" == "1" ]]; then
 fi
 echo "TG Commit: `git rev-parse --short HEAD 2>&1 || true`"
 
+./genrelations.sh
+
 # GEOS - used for benchmarking
 if [[ "$GEOS_BENCH" == "1" ]]; then
     CFLAGS="$CFLAGS -DGEOS_BENCH"
@@ -185,6 +196,8 @@ else
         fi
         if [[ "$VALGRIND" == "1" ]]; then
             valgrind --leak-check=yes ./$f.test $@
+        elif [[ "$CC" == "emcc" ]]; then
+            node ./$f.test $@
         else
             ./$f.test $@
         fi
diff --git a/tests/test_relations.c b/tests/test_relations.c
index 27a70e0..91f2b5b 100644
--- a/tests/test_relations.c
+++ b/tests/test_relations.c
@@ -412,53 +412,40 @@ static bool test_case(const char *path, const char *org_json,
     return ok;
 }
 
-static bool test_relation_file(const char *name) {
+static bool test_relation_file(struct relation *rel) {
     bool ok = true;
-    char path[512];
-    snprintf(path, sizeof(path), "relations/%s", name);
-    FILE *f = fopen(path, "rb");
-    assert(f);
-    fseek(f, 0, SEEK_END);
-    size_t sz = ftell(f);
-    char *jsrc = malloc(sz+1);
+    char *jsrc = malloc(strlen(rel->data)+1);
     assert(jsrc);
-    rewind(f);
-    assert(fread(jsrc, 1, sz, f) == sz);
-    jsrc[sz] = '\0';
-    json_strip_jsonc(jsrc, sz);
+    strcpy(jsrc, rel->data);
+    json_strip_jsonc(jsrc, strlen(jsrc));
     if (!json_valid(jsrc)) {
-        fprintf(stderr, "invalid json: %s\n", path);
+        fprintf(stderr, "invalid json: %s\n", rel->name);
         abort();
     }
     struct json json = json_parse(jsrc);
     json = json_first(json);
     while (json_exists(json)) {
-        if (!test_case(name, jsrc, strlen(jsrc), json)) {
+        if (!test_case(rel->name, jsrc, strlen(jsrc), json)) {
             ok = false;
         }
         json = json_next(json);
     }
     free(jsrc);
-    fclose(f);
     return ok;
 }
 
 void test_relations_cases(void) {
     bool ok = true;
-    DIR *dp = opendir("./relations");
-    assert(dp);
-    struct dirent *ep;
-    while ((ep = readdir (dp)) != NULL) {
-        if (strstr(ep->d_name, ".json")) {
-            if (strstr(ep->d_name, only_file) || strcmp(only_file, "all") == 0)
-            {
-                if (!test_relation_file(ep->d_name)) {
-                    ok = false;
-                }
+    int nrelations = sizeof(relations) / sizeof(struct relation);
+    for (int i = 0; i < nrelations; i++) {
+        struct relation *rel = &relations[i];
+        if (strstr(rel->name, only_file) || strcmp(only_file, "all") == 0)
+        {
+            if (!test_relation_file(rel)) {
+                ok = false;
             }
         }
     }
-    closedir(dp);
     if (!ok) {
         exit(1);
     }
diff --git a/tests/test_wkb.c b/tests/test_wkb.c
index 5c6c85b..c3dc372 100644
--- a/tests/test_wkb.c
+++ b/tests/test_wkb.c
@@ -651,7 +651,7 @@ void test_wkb_max_depth() {
     char *wkt;
     struct tg_geom *geom;
     
-    int depths[] = { 1, 100 , 1000, 1023, 1024, 1025, 2000 };
+    int depths[] = { 1, 100, 1000, 1023, 1024, 1025, 2000 };
 
     for (size_t i = 0; i < sizeof(depths)/sizeof(int); i++) {
         wkt = make_deep_wkb(depths[i]);
diff --git a/tests/tests.h b/tests/tests.h
index 4044ed3..d77aab0 100644
--- a/tests/tests.h
+++ b/tests/tests.h
@@ -452,6 +452,7 @@ bool eqish(double a, double b) {
 #endif
 #pragma GCC diagnostic ignored "-Wextra"
 #pragma GCC diagnostic ignored "-Wunused-variable"
+#pragma GCC diagnostic ignored "-Woverlength-strings"
 
 size_t total_allocs = 0;
 size_t total_mem = 0;
@@ -776,4 +777,7 @@ struct tg_geom *load_geom(const char *name, enum tg_index ix) {
 struct tg_geom *load_geom_flipped(const char *name, enum tg_index ix) {
     return _load_geom(name, ix, true);
 }
+
+#include "relations.h" // Auto generated from "run.sh"
+
 #endif // TESTS_H
diff --git a/tg.c b/tg.c
index 2274c58..fd55cdd 100644
--- a/tg.c
+++ b/tg.c
@@ -12789,9 +12789,9 @@ static size_t parse_wkb(const uint8_t *wkb, size_t len, size_t i, int depth,
 
     // Set the 'swap' bool which indicates that the wkb numbers need swapping
     // to match the host endianness.
-#if BYTE_ORDER == BIG_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
     bool swap = wkb[i] == 1;
-#elif BYTE_ORDER == LITTLE_ENDIAN
+#elif __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
     bool swap = wkb[i] == 0;
 #else
     #error "cannot determine byte order"
@@ -12899,7 +12899,7 @@ static void write_wkb_type(struct writer *wr, const struct head *head) {
 }
 
 static void write_posn_wkb(struct writer *wr, struct tg_point posn) {
-#if BYTE_ORDER == LITTLE_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
     if (wr->count+16 < wr->n) {
         memcpy(wr->dst+wr->count, &posn, 16);
         wr->count += 16;
@@ -12912,7 +12912,7 @@ static void write_posn_wkb(struct writer *wr, struct tg_point posn) {
 
 static void write_posn_wkb_3(struct writer *wr, struct tg_point posn, double z)
 {
-#if BYTE_ORDER == LITTLE_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
     if (wr->count+24 < wr->n) {
         memcpy(wr->dst+wr->count, ((double[3]){posn.x, posn.y, z}), 24);
         wr->count += 24;
@@ -12927,7 +12927,7 @@ static void write_posn_wkb_3(struct writer *wr, struct tg_point posn, double z)
 static void write_posn_wkb_4(struct writer *wr, struct tg_point posn, 
     double z, double m)
 {
-#if BYTE_ORDER == LITTLE_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
     if (wr->count+32 < wr->n) {
         memcpy(wr->dst+wr->count, ((double[4]){posn.x, posn.y, z, m}), 32);
         wr->count += 32;
@@ -12944,7 +12944,7 @@ static int write_ring_points_wkb(struct writer *wr, const struct tg_ring *ring)
 {
     write_uint32le(wr, ring->npoints);
     size_t needed = ring->npoints*16;
-#if BYTE_ORDER == LITTLE_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
     if (wr->count+needed <= wr->n) {
         memcpy(wr->dst+wr->count, ring->points, needed);
         wr->count += needed;