diff --git a/makefile b/makefile
index ae3da55383..9108ecc6b5 100755
--- a/makefile
+++ b/makefile
@@ -261,7 +261,7 @@ endif
 input = List
 
 ifeq ($(use-clang),true)
-	build-cxx = clang -std=c++11
+	build-cxx = clang++ -std=c++11
 	build-cc = clang
 else
 	build-cxx = g++
@@ -302,7 +302,7 @@ cflags_debug_fast = -O0 -g3
 cflags_stress = -O0 -g3
 cflags_stress_major = -O0 -g3
 ifeq ($(use-clang),true)
-	cflags_fast = -O4 -g3
+	cflags_fast = -O3 -flto -g3
 	cflags_small = -Oz -g3
 else
 	cflags_fast = -O3 -g3
@@ -346,6 +346,18 @@ cflags = $(build-cflags)
 
 common-lflags = -lm -lz
 
+ifeq ($(use-clang),true)
+  ifeq ($(build-platform),darwin)
+    common-lflags += -Wl,-export_dynamic
+  else
+    ifneq ($(platform),windows)
+      common-lflags += -Wl,-E
+    else
+      common-lflags += -Wl,--export-all-symbols
+    endif
+  endif
+endif
+
 build-lflags = -lz -lpthread -ldl
 
 lflags = $(common-lflags) -lpthread -ldl
@@ -1657,7 +1669,7 @@ endif
 $(build)/%.o: $(lzma)/C/%.c
 	@echo "compiling $(@)"
 	@mkdir -p $(dir $(@))
-	$(cxx) $(cflags) $(no-error) -c $$($(windows-path) $(<)) $(call output,$(@))
+	$(cc) $(cflags) $(no-error) -c $$($(windows-path) $(<)) $(call output,$(@))
 
 $(vm-asm-objects): $(build)/%-asm.o: $(src)/%.$(asm-format)
 	$(compile-asm-object)
@@ -1771,7 +1783,7 @@ executable-objects = $(vm-objects) $(classpath-objects) $(driver-object) \
 	$(javahome-object) $(boot-javahome-object) $(lzma-decode-objects)
 
 unittest-executable-objects = $(unittest-objects) $(vm-objects) \
-	$(build)/util/arg-parser.o $(stub-objects)
+	$(build)/util/arg-parser.o $(stub-objects) $(lzma-decode-objects)
 
 ifeq ($(process),interpret)
 	unittest-executable-objects += $(all-codegen-target-objects)
diff --git a/src/avian/x86.h b/src/avian/x86.h
index e428e1dd04..cbccf8f592 100644
--- a/src/avian/x86.h
+++ b/src/avian/x86.h
@@ -30,8 +30,8 @@
 
 #ifdef __APPLE__
 #  include "mach/mach_types.h"
-#  include "mach/i386/thread_act.h"
-#  include "mach/i386/thread_status.h"
+#  include "mach/thread_act.h"
+#  include "mach/thread_status.h"
 
 #  if __DARWIN_UNIX03 && defined(_STRUCT_X86_EXCEPTION_STATE32)
 #    define FIELD(x) __##x
diff --git a/src/classpath-openjdk.cpp b/src/classpath-openjdk.cpp
index 0cf5e3b465..0232c30b44 100644
--- a/src/classpath-openjdk.cpp
+++ b/src/classpath-openjdk.cpp
@@ -284,7 +284,9 @@ struct JmmInterface {
 
 const unsigned InterfaceVersion = 4;
 const unsigned PageSize = 4 * 1024;
+#ifdef AVIAN_OPENJDK_SRC
 const int VirtualFileBase = 1000000000;
+#endif
 
 Machine* globalMachine;
 
diff --git a/src/compile.cpp b/src/compile.cpp
index 8bce364b55..75fee5a7d4 100644
--- a/src/compile.cpp
+++ b/src/compile.cpp
@@ -50,7 +50,9 @@ const bool DebugNatives = false;
 const bool DebugCallTable = false;
 const bool DebugMethodTree = false;
 const bool DebugFrameMaps = false;
+#ifndef NDEBUG
 const bool DebugIntrinsics = false;
+#endif
 
 const bool CheckArrayBounds = true;
 
diff --git a/src/tools/type-generator/main.cpp b/src/tools/type-generator/main.cpp
index cdcb6c9874..8461d9f3e5 100644
--- a/src/tools/type-generator/main.cpp
+++ b/src/tools/type-generator/main.cpp
@@ -27,7 +27,7 @@
 
 #define UNUSED __attribute__((unused))
 
-inline void operator delete(void*) { abort(); }
+void operator delete(void*) { abort(); }
 
 extern "C" void __cxa_pure_virtual(void) { abort(); }