diff --git a/etc/config.csh/unset b/etc/config.csh/unset
index 0d531b5082..ce5a2e818a 100644
--- a/etc/config.csh/unset
+++ b/etc/config.csh/unset
@@ -106,6 +106,11 @@ unsetenv FOAM_USER_APPBIN
 unsetenv FOAM_USER_LIBBIN
 unsetenv FOAM_UTILITIES
 
+# Build related
+unsetenv FOAM_BUILDROOT
+unsetenv FOAM_THIRD_PARTY_BUILDROOT
+unsetenv FOAM_THIRD_PARTY_SOURCES
+
 # Older, unused variables
 
 # Before 1812
diff --git a/etc/config.sh/unset b/etc/config.sh/unset
index 6ed8599394..ebc9c38c7c 100644
--- a/etc/config.sh/unset
+++ b/etc/config.sh/unset
@@ -95,6 +95,11 @@ unset FOAM_USER_APPBIN
 unset FOAM_USER_LIBBIN
 unset FOAM_UTILITIES
 
+# Build related
+unset FOAM_BUILDROOT
+unset FOAM_THIRD_PARTY_BUILDROOT
+unset FOAM_THIRD_PARTY_SOURCES
+
 # Older, unused variables
 
 # Before 1812
diff --git a/tutorials/combustion/fireFoam/LES/compartmentFire/validation/plot b/tutorials/combustion/fireFoam/LES/compartmentFire/validation/plot
index 8d196a2dff..541c2b7e91 100755
--- a/tutorials/combustion/fireFoam/LES/compartmentFire/validation/plot
+++ b/tutorials/combustion/fireFoam/LES/compartmentFire/validation/plot
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 createEpsT()
 {