diff --git a/Test/ConstantString.m b/Test/ConstantString.m
index 8d3811c..4e7f720 100644
--- a/Test/ConstantString.m
+++ b/Test/ConstantString.m
@@ -1,19 +1,10 @@
 #import "Test.h"
 #include <string.h>
 
-@interface NSConstantString : Test
-{
-	const char * const str;
-	const unsigned int len;
-}
-- (unsigned int)length;
-- (const char*)cString;
-@end
-
 @implementation NSConstantString
 - (unsigned int)length
 {
-	return len;
+	return length;
 }
 - (const char*)cString
 {
diff --git a/Test/Test.h b/Test/Test.h
index e455aaa..36a5a2b 100644
--- a/Test/Test.h
+++ b/Test/Test.h
@@ -23,6 +23,27 @@ __attribute__((objc_root_class))
 #endif
 @end
 
+#ifdef __OBJC_GNUSTEP_RUNTIME_ABI__
+#	if __OBJC_GNUSTEP_RUNTIME_ABI__ >= 20
+#		define NEW_ABI
+#	endif
+#endif
+
+@interface NSConstantString : Test
+{
+#ifdef NEW_ABI
+	uint32_t flags;
+	uint32_t length;
+	uint32_t size;
+	uint32_t hash;
+	const char * const str;
+#else
+	const char * const str;
+	const unsigned int length;
+#endif
+}
+@end
+
 @interface NSAutoreleasePool : Test
 @end
 
diff --git a/Test/Test.m b/Test/Test.m
index 87bfcae..9edf209 100644
--- a/Test/Test.m
+++ b/Test/Test.m
@@ -8,3 +8,5 @@
 #define SINGLE_FILE_TEST 1
 #endif
 #include "Test.h"
+
+@implementation NSConstantString @end