diff --git a/libimagtag/Cargo.toml b/libimagtag/Cargo.toml
index 0fd71402..77ccf5af 100644
--- a/libimagtag/Cargo.toml
+++ b/libimagtag/Cargo.toml
@@ -8,6 +8,7 @@ clap = "2.1.1"
 log = "0.3.5"
 regex = "0.1.47"
 toml = "0.1.25"
+itertools = "0.4.7"
 
 [dependencies.libimagstore]
 path = "../libimagstore"
diff --git a/libimagtag/src/lib.rs b/libimagtag/src/lib.rs
index edded91b..c5fbc7a3 100644
--- a/libimagtag/src/lib.rs
+++ b/libimagtag/src/lib.rs
@@ -1,4 +1,5 @@
 extern crate clap;
+extern crate itertools;
 #[macro_use] extern crate log;
 extern crate regex;
 extern crate toml;
diff --git a/libimagtag/src/tagable.rs b/libimagtag/src/tagable.rs
index 70eaec02..bd478a97 100644
--- a/libimagtag/src/tagable.rs
+++ b/libimagtag/src/tagable.rs
@@ -1,6 +1,8 @@
 use std::ops::Deref;
 use std::ops::DerefMut;
 
+use itertools::Itertools;
+
 use libimagstore::store::{Entry, EntryHeader, FileLockEntry};
 
 use error::{TagError, TagErrorKind};
@@ -66,7 +68,7 @@ impl Tagable for EntryHeader {
             return Err(TagError::new(TagErrorKind::NotATag, None));
         }
 
-        let a = ts.iter().map(|t| Value::String(t.clone())).collect();
+        let a = ts.iter().unique().map(|t| Value::String(t.clone())).collect();
         self.set("imag.tags", Value::Array(a))
             .map(|_| ())
             .map_err(|e| TagError::new(TagErrorKind::HeaderWriteError, Some(Box::new(e))))
@@ -81,7 +83,7 @@ impl Tagable for EntryHeader {
         self.get_tags()
             .map(|mut tags| {
                 tags.push(t);
-                self.set_tags(tags)
+                self.set_tags(tags.into_iter().unique().collect())
             })
             .map(|_| ())
     }