diff --git a/src/buildvm_asm.c b/src/buildvm_asm.c
index 94e62ce7..6a860c9f 100644
--- a/src/buildvm_asm.c
+++ b/src/buildvm_asm.c
@@ -191,8 +191,7 @@ void emit_asm(BuildCtx *ctx)
   if (ctx->mode != BUILD_machasm)
     fprintf(ctx->fp, ".Lbegin:\n");
 
-#if LJ_TARGET_ARM && defined(__GNUC__) && !defined(__symbian__) && \
-    !LJ_TARGET_OSX
+#if LJ_TARGET_ARM && defined(__GNUC__) && !defined(LUAJIT_NO_UNWIND)
   /* This should really be moved into buildvm_arm.dasc. */
   fprintf(ctx->fp,
 	  ".fnstart\n"
@@ -228,8 +227,7 @@ void emit_asm(BuildCtx *ctx)
 #endif
   }
 
-#if LJ_TARGET_ARM && defined(__GNUC__) && !defined(__symbian__) && \
-    !LJ_TARGET_OSX
+#if LJ_TARGET_ARM && defined(__GNUC__) && !defined(LUAJIT_NO_UNWIND)
   fprintf(ctx->fp,
 	  ".globl lj_err_unwind_arm\n"
 	  ".personality lj_err_unwind_arm\n"
diff --git a/src/lj_arch.h b/src/lj_arch.h
index 355474fb..80ab051e 100644
--- a/src/lj_arch.h
+++ b/src/lj_arch.h
@@ -279,4 +279,16 @@
 #define LJ_64			1
 #endif
 
+/* Various workarounds for embedded operating systems. */
+#if defined(__ANDROID__) || defined(__symbian__)
+#define LUAJIT_NO_LOG2
+#endif
+#if defined(__symbian__)
+#define LUAJIT_NO_EXP2
+#endif
+
+#if defined(__symbian__) || (LJ_TARGET_ARM && LJ_TARGET_OSX)
+#define LUAJIT_NO_UNWIND
+#endif
+
 #endif
diff --git a/src/lj_err.c b/src/lj_err.c
index 63c5a22d..406c833d 100644
--- a/src/lj_err.c
+++ b/src/lj_err.c
@@ -178,8 +178,7 @@ static void *err_unwind(lua_State *L, void *stopcf, int errcode)
 
 /* -- External frame unwinding -------------------------------------------- */
 
-#if defined(__GNUC__) && !defined(__symbian__) && \
-    !(LJ_TARGET_ARM && LJ_TARGET_OSX)
+#if defined(__GNUC__) && !defined(LUAJIT_NO_UNWIND)
 
 #ifdef __clang__
 /* http://llvm.org/bugs/show_bug.cgi?id=8703 */
diff --git a/src/lj_vm.h b/src/lj_vm.h
index 3f6777ad..5a82dab0 100644
--- a/src/lj_vm.h
+++ b/src/lj_vm.h
@@ -66,12 +66,12 @@ LJ_ASMF void lj_vm_powi_sse(void);
 #else
 LJ_ASMF double lj_vm_trunc(double);
 LJ_ASMF double lj_vm_powi(double, int32_t);
-#if defined(__ANDROID__) || defined(__symbian__)
+#ifdef LUAJIT_NO_LOG2
 LJ_ASMF double lj_vm_log2(double);
 #else
 #define lj_vm_log2	log2
 #endif
-#if defined(__symbian__)
+#ifdef LUAJIT_NO_EXP2
 LJ_ASMF double lj_vm_exp2(double);
 #else
 #define lj_vm_exp2	exp2
diff --git a/src/lj_vmmath.c b/src/lj_vmmath.c
index 46f06504..ec3d98af 100644
--- a/src/lj_vmmath.c
+++ b/src/lj_vmmath.c
@@ -25,14 +25,14 @@ LJ_FUNCA double lj_vm_tanh(double x) { return tanh(x); }
 
 #if LJ_HASJIT
 
-#if defined(__ANDROID__) || defined(__symbian__)
+#ifdef LUAJIT_NO_LOG2
 double lj_vm_log2(double a)
 {
   return log(a) * 1.4426950408889634074;
 }
 #endif
 
-#if defined(__symbian__)
+#ifdef LUAJIT_NO_EXP2
 double lj_vm_exp2(double a)
 {
   return exp(a * 0.6931471805599453);