diff --git a/config/config.mk b/config/config.mk
index 62f8e30d260d..e72058d238ad 100644
--- a/config/config.mk
+++ b/config/config.mk
@@ -108,6 +108,13 @@ ifneq (,$(filter no-pymake,$(subst $(comma), ,$(MOZ_PSEUDO_DERECURSE))))
 MOZ_PSEUDO_DERECURSE :=
 endif
 endif
+
+# Disable MOZ_PSEUDO_DERECURSE on the second PGO pass until it's widely
+# tested.
+ifdef MOZ_PROFILE_USE
+MOZ_PSEUDO_DERECURSE :=
+endif
+
 #
 # Strip off the excessively long version numbers on these platforms,
 # but save the version to allow multiple versions of the same base
diff --git a/js/src/config/config.mk b/js/src/config/config.mk
index 62f8e30d260d..e72058d238ad 100644
--- a/js/src/config/config.mk
+++ b/js/src/config/config.mk
@@ -108,6 +108,13 @@ ifneq (,$(filter no-pymake,$(subst $(comma), ,$(MOZ_PSEUDO_DERECURSE))))
 MOZ_PSEUDO_DERECURSE :=
 endif
 endif
+
+# Disable MOZ_PSEUDO_DERECURSE on the second PGO pass until it's widely
+# tested.
+ifdef MOZ_PROFILE_USE
+MOZ_PSEUDO_DERECURSE :=
+endif
+
 #
 # Strip off the excessively long version numbers on these platforms,
 # but save the version to allow multiple versions of the same base