diff --git a/classpath/java-util-zip.cpp b/classpath/java-util-zip.cpp
index 17ac1ca1a0..b9e685fe4e 100644
--- a/classpath/java-util-zip.cpp
+++ b/classpath/java-util-zip.cpp
@@ -1,6 +1,6 @@
 #include "stdlib.h"
 #include "string.h"
-#include "zlib.h"
+#include "zlib-custom.h"
 
 #include "jni.h"
 #include "jni-util.h"
diff --git a/makefile b/makefile
index c24e663c10..02ee0cb687 100644
--- a/makefile
+++ b/makefile
@@ -8,6 +8,19 @@ ifeq ($(arch),i686)
 	arch = i386
 endif
 
+platform = $(shell uname -s)
+ifeq ($(platform),Darwin)
+	rdynamic =
+	thread-cflags =
+	shared = -dynamiclib
+	so-extension = dylib
+else
+	rdynamic = -rdynamic
+	thread-cflags = -pthread
+	shared = -shared
+	so-extension = so
+endif
+
 mode = debug
 
 bld = build/$(arch)/$(mode)
@@ -16,7 +29,7 @@ src = src
 classpath = classpath
 test = test
 
-input = $(cls)/GC.class
+input = $(cls)/Hello.class
 
 cxx = g++
 cc = gcc
@@ -30,7 +43,6 @@ show-size = :
 warnings = -Wall -Wextra -Werror -Wold-style-cast -Wunused-parameter \
 	-Winit-self -Wconversion
 
-thread-cflags = -pthread
 thread-lflags = -lpthread
 
 cflags = $(warnings) -fPIC -fno-rtti -fno-exceptions -fvisibility=hidden \
@@ -63,7 +75,7 @@ stdcpp-objects = $(call cpp-objects,$(stdcpp-sources),$(src))
 jni-sources = $(shell find $(classpath) -name '*.cpp')
 jni-objects = $(call cpp-objects,$(jni-sources),$(classpath))
 jni-cflags = -I$(JAVA_HOME)/include -I$(JAVA_HOME)/include/linux $(cflags)
-jni-library = $(bld)/libnatives.so
+jni-library = $(bld)/libnatives.$(so-extension)
 
 generated-code = \
 	$(bld)/type-enums.cpp \
@@ -213,11 +225,11 @@ $(jni-objects): $(bld)/%.o: $(classpath)/%.cpp
 
 $(jni-library): $(jni-objects)
 	@echo "linking $(@)"
-	$(cc) $(lflags) -shared $(^) -o $(@)
+	$(cc) $(lflags) $(shared) $(^) -o $(@)
 
 $(executable): $(interpreter-objects) $(stdcpp-objects)
 	@echo "linking $(@)"
-	$(cc) $(lflags) -rdynamic $(^) -o $(@)
+	$(cc) $(lflags) $(rdynamic) $(^) -o $(@)
 	@$(strip) --strip-all $(@)
 	@$(show-size) $(@)
 
diff --git a/src/builtin.cpp b/src/builtin.cpp
index 48dc22711e..cb15584d9a 100644
--- a/src/builtin.cpp
+++ b/src/builtin.cpp
@@ -1,4 +1,3 @@
-#include "builtin.h"
 #include "machine.h"
 #include "constants.h"
 #include "run.h"
diff --git a/src/cdecl.S b/src/cdecl.S
index 4abdc9aa09..9573eb9002 100644
--- a/src/cdecl.S
+++ b/src/cdecl.S
@@ -1,10 +1,10 @@
 #include "types.h"
 
 .text
-.globl cdeclCall
-.type cdeclCall, @function
+.globl _cdeclCall
+//.type cdeclCall, @function
    
-cdeclCall:
+_cdeclCall:
    pushl  %ebp
    movl   %esp,%ebp
 
diff --git a/src/common.h b/src/common.h
index 3f0ba59894..5c9646c51a 100644
--- a/src/common.h
+++ b/src/common.h
@@ -11,11 +11,14 @@
 
 #ifdef __i386__
 #  define LD "d"
+#  define ULD "lu"
 #  define LLD "lld"
 #elif defined __x86_64__
 #  define LD "ld"
+#  define ULD "lu"
 #  define LLD "ld"
-#  define LLD "ld"
+#else
+#error "Unsupported architecture"
 #endif
 
 #define NO_RETURN __attribute__((noreturn))
diff --git a/src/finder.cpp b/src/finder.cpp
index f543ad090e..e4f808c74b 100644
--- a/src/finder.cpp
+++ b/src/finder.cpp
@@ -1,4 +1,4 @@
-#include "zlib.h"
+#include "zlib-custom.h"
 #include "system.h"
 #include "finder.h"
 
diff --git a/src/machine.h b/src/machine.h
index 44266d1195..95c1528629 100644
--- a/src/machine.h
+++ b/src/machine.h
@@ -1663,7 +1663,7 @@ inline uint32_t
 popInt(Thread* t)
 {
   if (DebugStack) {
-    fprintf(stderr, "pop int %"LD" at %d\n",
+    fprintf(stderr, "pop int %"ULD" at %d\n",
             t->stack[((t->sp - 1) * 2) + 1],
             t->sp - 1);
   }
@@ -1721,7 +1721,7 @@ inline uint32_t
 peekInt(Thread* t, unsigned index)
 {
   if (DebugStack) {
-    fprintf(stderr, "peek int %"LD" at %d\n",
+    fprintf(stderr, "peek int %"ULD" at %d\n",
             t->stack[(index * 2) + 1],
             index);
   }
diff --git a/src/system.cpp b/src/system.cpp
index 021c54940c..12404c1646 100644
--- a/src/system.cpp
+++ b/src/system.cpp
@@ -25,7 +25,7 @@ cdeclCall(void* function, void* stack, unsigned stackSize,
 namespace {
 
 inline uint64_t
-dynamicCall(void* function, uint32_t* arguments, uint8_t*,
+dynamicCall(void* function, uintptr_t* arguments, uint8_t*,
             unsigned, unsigned argumentsSize, unsigned returnType)
 {
   return cdeclCall(function, arguments, argumentsSize, returnType);
@@ -511,7 +511,7 @@ class MySystem: public System {
       count -= *up;
 
       if (Verbose) {
-        fprintf(stderr, "free %"LD"; count: %d; limit: %d\n",
+        fprintf(stderr, "free %"ULD"; count: %d; limit: %d\n",
                 *up, count, limit);
       }
 
diff --git a/src/zlib-custom.h b/src/zlib-custom.h
new file mode 100644
index 0000000000..5f8cdb3c32
--- /dev/null
+++ b/src/zlib-custom.h
@@ -0,0 +1,7 @@
+#include "zlib.h"
+
+#ifdef inflateInit2
+#undef inflateInit2
+#define inflateInit2(strm, windowBits) \
+        inflateInit2_((strm), (windowBits), ZLIB_VERSION, static_cast<int>(sizeof(z_stream)))
+#endif