diff --git a/ObsoleteFiles.inc b/ObsoleteFiles.inc
--- a/ObsoleteFiles.inc
+++ b/ObsoleteFiles.inc
@@ -51,6 +51,9 @@
 #   xargs -n1 | sort | uniq -d;
 # done
 
+# 2025XXXX: sys/vm/stack test symbols moved to /usr/lib/debug
+OLD_DIRS+=usr/tests/sys/vm/stack/.debug
+
 # 20250129: libdevinfo bumped to version 7
 OLD_LIBS+=lib/libdevinfo.so.6
 
diff --git a/etc/mtree/BSD.debug.dist b/etc/mtree/BSD.debug.dist
--- a/etc/mtree/BSD.debug.dist
+++ b/etc/mtree/BSD.debug.dist
@@ -57,6 +57,12 @@
             sbin
             ..
             tests
+                sys
+                    vm
+                        stack
+                        ..
+                    ..
+                ..
             ..
         ..
     ..
diff --git a/share/mk/bsd.lib.mk b/share/mk/bsd.lib.mk
--- a/share/mk/bsd.lib.mk
+++ b/share/mk/bsd.lib.mk
@@ -254,7 +254,8 @@
 # Use ${DEBUGDIR} for base system debug files, else .debug subdirectory
 .if ${_SHLIBDIR} == "/boot" ||\
     ${SHLIBDIR:C%/lib(/.*)?$%/lib%} == "/lib" ||\
-    ${SHLIBDIR:C%/usr/(tests/)?lib(32|exec)?(/.*)?%/usr/lib%} == "/usr/lib"
+    ${SHLIBDIR:C%/usr/lib(32|exec)?(/.*)?%/usr/lib%} == "/usr/lib" ||
+    ${SHLIBDIR:C%/usr/tests(/.*)?%/usr/tests%} == "/usr/tests"
 DEBUGFILEDIR=${DEBUGDIR}${_SHLIBDIR}
 .else
 DEBUGFILEDIR=${_SHLIBDIR}/.debug