diff --git a/racket/src/configure b/racket/src/configure
index 1e3d02b1e9..6d95e527d4 100755
--- a/racket/src/configure
+++ b/racket/src/configure
@@ -3258,8 +3258,8 @@ if test "${enable_ios}" != "" ; then
      ;;
   esac
   IOS_PHONE_VERS="6.0"
-  PREFLAGS="$PREFLAGS -DTARGET_OS_IPHONE"
-  CPPFLAGS="$CPPFLAGS -DTARGET_OS_IPHONE"
+  PREFLAGS="$PREFLAGS -DTARGET_OS_IPHONE=1"
+  CPPFLAGS="$CPPFLAGS -DTARGET_OS_IPHONE=1"
   PREFLAGS="$PREFLAGS -arch ${IOS_ARCH} -isysroot ${ios_sdk} -miphoneos-version-min=${IOS_PHONE_VERS}"
   CPPFLAGS="$CPPFLAGS -arch ${IOS_ARCH} -isysroot ${ios_sdk} -miphoneos-version-min=${IOS_PHONE_VERS}"
   LDFLAGS="$LDFLAGS -arch ${IOS_ARCH} -isysroot ${ios_sdk} -miphoneos-version-min=${IOS_PHONE_VERS} -liconv"
diff --git a/racket/src/racket/configure.ac b/racket/src/racket/configure.ac
index 26583d2dde..48766f53d7 100644
--- a/racket/src/racket/configure.ac
+++ b/racket/src/racket/configure.ac
@@ -530,8 +530,8 @@ if test "${enable_ios}" != "" ; then
      ;;
   esac
   IOS_PHONE_VERS="6.0"
-  PREFLAGS="$PREFLAGS -DTARGET_OS_IPHONE"
-  CPPFLAGS="$CPPFLAGS -DTARGET_OS_IPHONE"
+  PREFLAGS="$PREFLAGS -DTARGET_OS_IPHONE=1"
+  CPPFLAGS="$CPPFLAGS -DTARGET_OS_IPHONE=1"
   PREFLAGS="$PREFLAGS -arch ${IOS_ARCH} -isysroot ${ios_sdk} -miphoneos-version-min=${IOS_PHONE_VERS}"
   CPPFLAGS="$CPPFLAGS -arch ${IOS_ARCH} -isysroot ${ios_sdk} -miphoneos-version-min=${IOS_PHONE_VERS}"
   LDFLAGS="$LDFLAGS -arch ${IOS_ARCH} -isysroot ${ios_sdk} -miphoneos-version-min=${IOS_PHONE_VERS} -liconv"
diff --git a/racket/src/racket/sconfig.h b/racket/src/racket/sconfig.h
index d378f54db6..4010dc6752 100644
--- a/racket/src/racket/sconfig.h
+++ b/racket/src/racket/sconfig.h
@@ -807,7 +807,7 @@
 
 # if defined(XONX)
 #  define SPLS_MAC "darwin"
-# elif defined(TARGET_OS_IPHONE)
+# elif TARGET_OS_IPHONE
 #  define SPLS_MAC "ios"
 # else
 #  define SPLS_MAC "macosx"
diff --git a/racket/src/racket/src/lightning/arm/core.h b/racket/src/racket/src/lightning/arm/core.h
index d987566217..af5e793796 100644
--- a/racket/src/racket/src/lightning/arm/core.h
+++ b/racket/src/racket/src/lightning/arm/core.h
@@ -53,7 +53,7 @@ jit_v_order[JIT_V_NUM] = {
 
 #define jit_no_set_flags()		jit_flags.no_set_flags
 
-#ifdef TARGET_OS_IPHONE
+#if TARGET_OS_IPHONE
 # define USE_SEPARATE_DIV_AND_MOD
 #endif
 
diff --git a/racket/src/racket/src/lightning/arm/funcs.h b/racket/src/racket/src/lightning/arm/funcs.h
index 3f35532ba8..574be1208a 100644
--- a/racket/src/racket/src/lightning/arm/funcs.h
+++ b/racket/src/racket/src/lightning/arm/funcs.h
@@ -42,7 +42,7 @@
 
 #define jit_notify_freed_code() /* empty */
 
-#ifdef TARGET_OS_IPHONE
+#if TARGET_OS_IPHONE
 void sys_icache_invalidate(void *start, size_t len);
 # define CLEAR_ICACHE(s, e) sys_icache_invalidate(s, ((char *)e) - ((char *)s));
 #else
diff --git a/racket/src/racket/src/string.c b/racket/src/racket/src/string.c
index 03b180a49e..a123f99dce 100644
--- a/racket/src/racket/src/string.c
+++ b/racket/src/racket/src/string.c
@@ -2157,7 +2157,7 @@ int scheme_any_string_has_null(Scheme_Object *o)
 /* Environment Variables                                               */
 /***********************************************************************/
 
-#if defined(OS_X) && !defined(TARGET_OS_IPHONE)
+#if defined(OS_X) && !TARGET_OS_IPHONE
 # include <crt_externs.h>
 # define GET_ENVIRON_ARRAY *_NSGetEnviron()
 #endif