diff --git a/log.py b/log.py
index c217e7e..47ea6cb 100644
--- a/log.py
+++ b/log.py
@@ -8,7 +8,7 @@ YELLOW = ""
 BOLD   = ""
 PLAIN  = ""
 
-if sys.stderr.isatty():
+if sys.stderr.isatty() and (os.environ.get('TERM') or 'dumb') != 'dumb':
     # ...use ANSI formatting codes.
     RED    = "\x1b[31m"
     GREEN  = "\x1b[32m"
diff --git a/minimal/do b/minimal/do
index e4b02ae..1d3c94a 100755
--- a/minimal/do
+++ b/minimal/do
@@ -12,7 +12,7 @@ GREEN=""
 BOLD=""
 PLAIN=""
 
-if tty <&2 >/dev/null 2>&1; then
+if [ -n "$TERM" -a "$TERM" != "dumb" ] && tty <&2 >/dev/null 2>&1; then
 	GREEN="$(printf '\033[32m')"
 	BOLD="$(printf '\033[1m')"
 	PLAIN="$(printf '\033[m')"