diff --git a/build_library/build_common.sh b/build_library/build_common.sh
index a6a9cfa0ac..09a31e6df4 100644
--- a/build_library/build_common.sh
+++ b/build_library/build_common.sh
@@ -42,7 +42,7 @@ copy_image() {
   local dst="${BUILD_DIR}/$2"
   if should_build_image $1; then
     echo "Creating $2 from $1..."
-    $COMMON_PV_CAT "${src}" >"${dst}" || die "Cannot copy $1 to $2"
+    $(pv_cat_cmd) "${src}" >"${dst}" || die "Cannot copy $1 to $2"
   else
     mv "${src}" "${dst}" || die "Cannot move $1 to $2"
   fi
diff --git a/common.sh b/common.sh
index 980d02717b..7d05f2b953 100644
--- a/common.sh
+++ b/common.sh
@@ -16,13 +16,22 @@ fi
 # Ensure that any sub scripts we invoke get the max proc count.
 export NUM_JOBS="${NUM_JOBS}"
 
-# True if we have the 'pv' utility - also set up COMMON_PV_CAT for convenience
-COMMON_PV_OK=1
-COMMON_PV_CAT=pv
-pv -V >/dev/null 2>&1 || COMMON_PV_OK=0
-if [ $COMMON_PV_OK -eq 0 ]; then
-  COMMON_PV_CAT=cat
-fi
+# Returns the pv command if it's available, otherwise plain-old cat. Note that
+# this function echoes the command, rather than running it, so it can be used
+# as an argument to other commands (like sudo).
+pv_cat_cmd() {
+  if pv -V >/dev/null 2>&1; then
+    # Limit pv's output to 80 columns, for readability.
+    local term_cols=$(stty size 2>/dev/null | cut -d' ' -f2)
+    if [ ${term_cols:-0} -gt 80 ]; then
+      echo pv -w 80
+    else
+      echo pv
+    fi
+  else
+    echo cat
+  fi
+}
 
 # Make sure we have the location and name of the calling script, using
 # the current value if it is already set.
diff --git a/image_to_usb.sh b/image_to_usb.sh
index 30a143272f..0395c002f4 100755
--- a/image_to_usb.sh
+++ b/image_to_usb.sh
@@ -350,7 +350,7 @@ if [ -b "${FLAGS_to}" ]; then
   fi
 
   if [ ${FLAGS_install} -ne ${FLAGS_TRUE} ]; then
-    sudo ${COMMON_PV_CAT} "${SRC_IMAGE}" |
+    sudo $(pv_cat_cmd) "${SRC_IMAGE}" |
       sudo dd of="${FLAGS_to}" bs=4M oflag=sync status=noxfer
     sync
   else
@@ -369,7 +369,7 @@ else
   # Output to a file, so just make a copy.
   if [ "${SRC_IMAGE}" != "${FLAGS_to}" ]; then
     echo "Copying image ${SRC_IMAGE} to file ${FLAGS_to}..."
-    ${COMMON_PV_CAT} "${SRC_IMAGE}" >"${FLAGS_to}"
+    $(pv_cat_cmd) "${SRC_IMAGE}" >"${FLAGS_to}"
   fi
 
   info "To copy onto a USB/MMC drive /dev/sdX, use: "