diff --git a/Makefile b/Makefile
index 3968a661..f5c19a1f 100644
--- a/Makefile
+++ b/Makefile
@@ -69,7 +69,7 @@ JANET_BOOT_OBJECTS=$(patsubst src/%.c,build/%.boot.o,$(JANET_CORE_SOURCES) $(JAN
 	build/core.gen.o \
 	build/boot.gen.o
 
-build/%.boot.o: src/%.c
+build/%.boot.o: src/%.c $(JANET_HEADERS) $(JANET_LOCAL_HEADERS)
 	$(CC) $(CFLAGS) -DJANET_BOOTSTRAP -o $@ -c $<
 
 build/janet_boot: $(JANET_BOOT_OBJECTS)
@@ -191,7 +191,8 @@ callgrind: $(JANET_TARGET)
 
 dist: build/janet-dist.tar.gz
 
-build/janet-%.tar.gz: $(JANET_TARGET) src/include/janet.h \
+build/janet-%.tar.gz: $(JANET_TARGET) \
+	src/include/janet.h src/include/janetconf.h \
 	janet.1 LICENSE CONTRIBUTING.md $(JANET_LIBRARY) \
 	build/doc.html README.md build/janet.c
 	tar -czvf $@ $^
@@ -230,8 +231,8 @@ install: $(JANET_TARGET)
 	cp $(JANET_HEADERS) $(INCLUDEDIR)
 	mkdir -p $(INCLUDEDIR)/janet
 	mkdir -p $(JANET_PATH)
-	ln -sf $(INCLUDEDIR)/janet.h $(INCLUDEDIR)/janet/janet.h
 	ln -sf $(INCLUDEDIR)/janet.h $(JANET_PATH)/janet.h
+	ln -sf $(INCLUDEDIR)/janetconf.h $(JANET_PATH)/janetconf.h
 	cp tools/cook.janet $(JANET_PATH)
 	cp tools/highlight.janet $(JANET_PATH)
 	cp tools/bars.janet $(JANET_PATH)
diff --git a/src/core/corelib.c b/src/core/corelib.c
index 1f86c77a..81b47c89 100644
--- a/src/core/corelib.c
+++ b/src/core/corelib.c
@@ -41,7 +41,7 @@ extern size_t janet_core_image_size;
 #if defined(JANET_NO_DYNAMIC_MODULES)
 typedef int Clib;
 #define load_clib(name) ((void) name, 0)
-#define symbol_clib(lib, sym) ((void) lib, (void) sym, 0)
+#define symbol_clib(lib, sym) ((void) lib, (void) sym, NULL)
 #define error_clib() "dynamic libraries not supported"
 #elif defined(JANET_WINDOWS)
 #include <windows.h>
diff --git a/src/core/typedarray.c b/src/core/typedarray.c
index 7260384e..7400ad3e 100644
--- a/src/core/typedarray.c
+++ b/src/core/typedarray.c
@@ -20,15 +20,13 @@
 * IN THE SOFTWARE.
 */
 
-/* Compiler feature test macros for things */
-#define _DEFAULT_SOURCE
-#define _BSD_SOURCE
-
 #ifndef JANET_AMALG
 #include <janet.h>
 #include "util.h"
 #endif
 
+#ifdef JANET_TYPED_ARRAY
+
 static char *ta_type_names[] = {
     "uint8",
     "int8",
@@ -559,3 +557,5 @@ void janet_lib_typed_array(JanetTable *env) {
     janet_register_abstract_type(&ta_buffer_type);
     janet_register_abstract_type(&ta_view_type);
 }
+
+#endif
diff --git a/src/include/janet.h b/src/include/janet.h
index 8f983749..088d1b14 100644
--- a/src/include/janet.h
+++ b/src/include/janet.h
@@ -29,7 +29,11 @@ extern "C" {
 
 /***** START SECTION CONFIG *****/
 
-#define JANET_VERSION "0.4.1"
+#include "janetconf.h"
+
+#ifndef JANET_VERSION
+#define JANET_VERSION "latest"
+#endif
 
 #ifndef JANET_BUILD
 #define JANET_BUILD "local"
diff --git a/src/include/janetconf.h b/src/include/janetconf.h
new file mode 100644
index 00000000..267b8036
--- /dev/null
+++ b/src/include/janetconf.h
@@ -0,0 +1,46 @@
+/*
+* Copyright (c) 2019 Calvin Rose
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy
+* of this software and associated documentation files (the "Software"), to
+* deal in the Software without restriction, including without limitation the
+* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+* sell copies of the Software, and to permit persons to whom the Software is
+* furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in
+* all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+* IN THE SOFTWARE.
+*/
+
+/* Configure Janet. Edit this file to customize the build */
+
+#ifndef JANETCONF_H
+#define JANETCONF_H
+
+#define JANET_VERSION "0.4.1"
+
+/* #define JANET_BUILD "local" */
+/* #define JANET_SINGLE_THREADED */
+/* #define JANET_NO_DYNAMIC_MODULES */
+/* #define JANET_NO_ASSEMBLER */
+/* #define JANET_NO_PEG */
+/* #define JANET_NO_TYPED_ARRAY */
+/* #define JANET_NO_INT_TYPES */
+/* #define JANET_API __attribute__((visibility ("default"))) */
+/* #define JANET_OUT_OF_MEMORY do { printf("janet out of memory\n"); exit(1); } while (0) */
+/* #define JANET_RECURSION_GUARD 1024 */
+/* #define JANET_MAX_PROTO_DEPTH 200 */
+/* #define JANET_MAX_MACRO_EXPAND 200 */
+/* #define JANET_STACK_MAX 16384 */
+/* #define JANET_NO_NANBOX */
+/* #define JANET_WALIGN 8 */
+
+#endif /* end of include guard: JANETCONF_H */