diff --git a/src/arch/arm/freebsd/fs_workload.cc b/src/arch/arm/freebsd/fs_workload.cc
index 959581bd8d..d6e9533811 100644
--- a/src/arch/arm/freebsd/fs_workload.cc
+++ b/src/arch/arm/freebsd/fs_workload.cc
@@ -45,7 +45,7 @@
 #include "mem/physical.hh"
 #include "sim/stat_control.hh"
 
-using namespace FreeBSD;
+using namespace free_bsd;
 
 namespace ArmISA
 {
diff --git a/src/arch/generic/freebsd/threadinfo.hh b/src/arch/generic/freebsd/threadinfo.hh
index 28184e7907..6c89450589 100644
--- a/src/arch/generic/freebsd/threadinfo.hh
+++ b/src/arch/generic/freebsd/threadinfo.hh
@@ -36,7 +36,9 @@
 #include "cpu/thread_context.hh"
 #include "sim/system.hh"
 
-namespace FreeBSD {
+GEM5_DEPRECATED_NAMESPACE(FreeBSD, free_bsd);
+namespace free_bsd
+{
 
 class ThreadInfo
 {
@@ -54,6 +56,6 @@ class ThreadInfo
     {}
 };
 
-} // namespace FreeBSD
+} // namespace free_bsd
 
 #endif // __ARCH_GENERIC_FREEBSD_THREADINFO_HH__
diff --git a/src/kern/freebsd/events.cc b/src/kern/freebsd/events.cc
index 0a78076886..08b938bd3e 100644
--- a/src/kern/freebsd/events.cc
+++ b/src/kern/freebsd/events.cc
@@ -40,7 +40,8 @@
 #include "kern/system_events.hh"
 #include "sim/system.hh"
 
-namespace FreeBSD
+GEM5_DEPRECATED_NAMESPACE(FreeBSD, free_bsd);
+namespace free_bsd
 {
 
 void
@@ -60,4 +61,4 @@ onUDelay(ThreadContext *tc, uint64_t div, uint64_t mul, uint64_t time)
         tc->quiesceTick(curTick() + sim_clock::Int::ns * time);
 }
 
-} // namespace FreeBSD
+} // namespace free_bsd
diff --git a/src/kern/freebsd/events.hh b/src/kern/freebsd/events.hh
index ebf6128be6..884b36a8ee 100644
--- a/src/kern/freebsd/events.hh
+++ b/src/kern/freebsd/events.hh
@@ -33,10 +33,12 @@
 #ifndef __KERN_FREEBSD_EVENTS_HH__
 #define __KERN_FREEBSD_EVENTS_HH__
 
+#include "base/compiler.hh"
 #include "kern/system_events.hh"
 #include "sim/guest_abi.hh"
 
-namespace FreeBSD
+GEM5_DEPRECATED_NAMESPACE(FreeBSD, free_bsd);
+namespace free_bsd
 {
 
 void onUDelay(ThreadContext *tc, uint64_t div, uint64_t mul, uint64_t time);