diff --git a/kernel/external-module-compat.h b/kernel/external-module-compat.h
index c28d759..1ad515f 100644
--- a/kernel/external-module-compat.h
+++ b/kernel/external-module-compat.h
@@ -349,10 +349,14 @@ uint64_t div64_u64(uint64_t dividend, uint64_t divisor);
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 
+#if !defined(RHEL_RELEASE_CODE) || (RHEL_RELEASE_CODE < RHEL_RELEASE_VERSION(5,2))
+
 typedef _Bool bool;
 
 #endif
 
+#endif
+
 /*
  * PF_VCPU is a Linux 2.6.24 addition
  */