diff --git a/optipdf b/optipdf
index aa48c72..b2db85d 100755
--- a/optipdf
+++ b/optipdf
@@ -4,7 +4,8 @@
 PRESERVE_TIMESTAMP=0
 LOSSY=0
 KEEP_BACKUP_SUFFIX=.old-unoptimized
-FORCE=0
+FORCE_OVERWRITE=0
+ENCODE_THRU_WARNINGS=0
 
 TEMP_FILES=()
 cleanup() {
@@ -24,11 +25,17 @@ for ARG; do
             --no-backup)
                 KEEP_BACKUP_SUFFIX=
                 ;;
-            --force|-f)
-                FORCE=1
+            --careful)
+                ENCODE_THRU_WARNINGS=0
                 ;;
-            --no-force|--careful)
-                FORCE=0
+            --no-careful)
+                ENCODE_THRU_WARNINGS=1
+                ;;
+            --force|-f)
+                FORCE_OVERWRITE=1
+                ;;
+            --no-force)
+                FORCE_OVERWRITE=0
                 ;;
             --lossy)
                 LOSSY=1
@@ -110,7 +117,12 @@ use_smaller() {
         FILE=$1 \
         TEMP=$2 \
         ORIGSIZE \
-        TEMPSIZE
+        TEMPSIZE \
+        MV_ARGS=('-v')
+
+    if [[ $FORCE_OVERWRITE -eq 0 ]]; then
+        MV_ARGS+=('-i')
+    fi
 
     ORIGSIZE=$(file_size "$FILE")
     TEMPSIZE=$(file_size "$TEMP")
@@ -143,7 +155,7 @@ use_smaller() {
         fi &&
 
         if [[ -n $KEEP_BACKUP_SUFFIX ]]; then
-            mv -vi -- "$FILE" "$FILE$KEEP_BACKUP_SUFFIX"
+            mv "${MV_ARGS[@]}" -- "$FILE" "$FILE$KEEP_BACKUP_SUFFIX"
         fi &&
 
         cp \
@@ -181,7 +193,7 @@ if [[ $LOSSY -ne 0 ]]; then
         --optimize-images
     )
 fi
-if [[ $FORCE -ne 0 ]]; then
+if [[ $ENCODE_THRU_WARNINGS -ne 0 ]]; then
     QPDF_ARGS+=(
         --warning-exit-0
     )