diff --git a/content/smil/defs.mk b/content/smil/defs.mk
new file mode 100644
index 000000000000..4e2c31152dea
--- /dev/null
+++ b/content/smil/defs.mk
@@ -0,0 +1,3 @@
+ifeq ($(OS_TARGET),WINNT)
+NO_PROFILE_GUIDED_OPTIMIZE := 1 # Don't PGO
+endif
diff --git a/content/svg/defs.mk b/content/svg/defs.mk
new file mode 100644
index 000000000000..4e2c31152dea
--- /dev/null
+++ b/content/svg/defs.mk
@@ -0,0 +1,3 @@
+ifeq ($(OS_TARGET),WINNT)
+NO_PROFILE_GUIDED_OPTIMIZE := 1 # Don't PGO
+endif
diff --git a/layout/svg/defs.mk b/layout/svg/defs.mk
new file mode 100644
index 000000000000..4e2c31152dea
--- /dev/null
+++ b/layout/svg/defs.mk
@@ -0,0 +1,3 @@
+ifeq ($(OS_TARGET),WINNT)
+NO_PROFILE_GUIDED_OPTIMIZE := 1 # Don't PGO
+endif