diff --git a/src/main.rs b/src/main.rs
index 6218e71..cc59337 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -79,6 +79,12 @@ fn main() {
             .required(false)
             .takes_value(false)
             .help("Install packages avoiding the GIT package provider. Try this flag if the default mode is not working."))
+        .arg(Arg::with_name("external")
+            .short("e")
+            .long("external")
+            .required(false)
+            .takes_value(false)
+            .help("Allow installing packages from non-verified repositories."))
         .arg(Arg::with_name("package_name")
             .help("Package name"));
 
@@ -766,6 +772,13 @@ fn install_main(_config_set: ConfigSet, matches: &ArgMatches) {
         Box::new(GitPackageResolver::new())
     };
 
+    let allow_external: bool = if matches.is_present("external") {
+        println!("Allowing external repositories");
+        true
+    }else{
+        false
+    };
+
     let mut package_manager = DefaultPackageManager::new_default(Some(package_resolver));
 
     if package_manager.is_index_outdated() {
@@ -792,7 +805,7 @@ fn install_main(_config_set: ConfigSet, matches: &ArgMatches) {
         println!("Using cached package index, run 'espanso package refresh' to update it.")
     }
 
-    let res = package_manager.install_package(package_name);
+    let res = package_manager.install_package(package_name, allow_external);
 
     match res {
         Ok(install_result) => {
@@ -812,6 +825,22 @@ fn install_main(_config_set: ConfigSet, matches: &ArgMatches) {
                 InstallResult::AlreadyInstalled => {
                     eprintln!("{} already installed!", package_name);
                 },
+                InstallResult::BlockedExternalPackage(repo_url) => {
+                    eprintln!("Warning: the requested package is hosted on an external repository:");
+                    eprintln!();
+                    eprintln!("{}", repo_url);
+                    eprintln!();
+                    eprintln!("and its contents may not have been verified by espanso.");
+                    eprintln!();
+                    eprintln!("For your security, espanso blocks packages that are not verified.");
+                    eprintln!("If you want to install the package anyway, you can force espanso");
+                    eprintln!("to install it with the following command, but please do it only");
+                    eprintln!("if you trust the source or you verified the contents of the package");
+                    eprintln!("by checking out the repository listed above.");
+                    eprintln!();
+                    eprintln!("espanso install {} --external", package_name);
+                    eprintln!();
+                }
                 InstallResult::Installed => {
                     println!("{} successfully installed!", package_name);
                     println!();
diff --git a/src/package/default.rs b/src/package/default.rs
index d3bbd7f..10cebfa 100644
--- a/src/package/default.rs
+++ b/src/package/default.rs
@@ -24,7 +24,7 @@ use std::fs::{File, create_dir};
 use std::io::{BufReader, BufRead};
 use std::time::{SystemTime, UNIX_EPOCH};
 use crate::package::UpdateResult::{NotOutdated, Updated};
-use crate::package::InstallResult::{NotFoundInIndex, AlreadyInstalled};
+use crate::package::InstallResult::{NotFoundInIndex, AlreadyInstalled, BlockedExternalPackage};
 use std::fs;
 use tempfile::TempDir;
 use git2::Repository;
@@ -138,13 +138,31 @@ impl DefaultPackageManager {
                 return None
             }
 
+            let original_repo = if fields.contains_key("package_original_repo") {
+                fields.get("package_original_repo").unwrap().clone()
+            }else{
+                fields.get("package_repo").unwrap().clone()
+            };
+
+            let is_core = if fields.contains_key("is_core") {
+                match fields.get("is_core").unwrap().clone().as_ref() {
+                    "true" => true,
+                    "false" => false,
+                    _ => false,
+                }
+            }else{
+                false
+            };
+
             let package = Package {
                 name: fields.get("package_name").unwrap().clone(),
                 title: fields.get("package_title").unwrap().clone(),
                 version: fields.get("package_version").unwrap().clone(),
                 repo: fields.get("package_repo").unwrap().clone(),
                 desc: fields.get("package_desc").unwrap().clone(),
-                author: fields.get("package_author").unwrap().clone()
+                author: fields.get("package_author").unwrap().clone(),
+                is_core,
+                original_repo
             };
 
             Some(package)
@@ -228,11 +246,15 @@ impl super::PackageManager for DefaultPackageManager {
         None
     }
 
-    fn install_package(&self, name: &str) -> Result<InstallResult, Box<dyn Error>> {
+    fn install_package(&self, name: &str, allow_external: bool) -> Result<InstallResult, Box<dyn Error>> {
         let package = self.get_package(name);
         match package {
             Some(package) => {
-                self.install_package_from_repo(name, &package.repo)
+                if package.is_core || allow_external {
+                    self.install_package_from_repo(name, &package.repo)
+                }else{
+                    Ok(BlockedExternalPackage(package.original_repo))
+                }
             },
             None => {
                 Ok(NotFoundInIndex)
@@ -451,7 +473,7 @@ mod tests {
             std::fs::write(index_file, INSTALL_PACKAGE_INDEX);
         });
 
-        assert_eq!(temp.package_manager.install_package("doesnotexist").unwrap(), NotFoundInIndex);
+        assert_eq!(temp.package_manager.install_package("doesnotexist", false).unwrap(), NotFoundInIndex);
     }
 
     #[test]
@@ -462,7 +484,7 @@ mod tests {
             std::fs::write(index_file, INSTALL_PACKAGE_INDEX);
         });
 
-        assert_eq!(temp.package_manager.install_package("italian-accents").unwrap(), AlreadyInstalled);
+        assert_eq!(temp.package_manager.install_package("italian-accents", false).unwrap(), AlreadyInstalled);
     }
 
     #[test]
@@ -472,7 +494,7 @@ mod tests {
             std::fs::write(index_file, INSTALL_PACKAGE_INDEX);
         });
 
-        assert_eq!(temp.package_manager.install_package("dummy-package").unwrap(), Installed);
+        assert_eq!(temp.package_manager.install_package("dummy-package", false).unwrap(), Installed);
         assert!(temp.package_dir.path().join("dummy-package").exists());
         assert!(temp.package_dir.path().join("dummy-package/README.md").exists());
         assert!(temp.package_dir.path().join("dummy-package/package.yml").exists());
@@ -485,7 +507,7 @@ mod tests {
             std::fs::write(index_file, INSTALL_PACKAGE_INDEX);
         });
 
-        assert_eq!(temp.package_manager.install_package("not-existing").unwrap(), NotFoundInRepo);
+        assert_eq!(temp.package_manager.install_package("not-existing", false).unwrap(), NotFoundInRepo);
     }
 
     #[test]
@@ -495,7 +517,7 @@ mod tests {
             std::fs::write(index_file, INSTALL_PACKAGE_INDEX);
         });
 
-        assert_eq!(temp.package_manager.install_package("dummy-package2").unwrap(), MissingPackageVersion);
+        assert_eq!(temp.package_manager.install_package("dummy-package2", false).unwrap(), MissingPackageVersion);
     }
 
     #[test]
@@ -505,7 +527,7 @@ mod tests {
             std::fs::write(index_file, INSTALL_PACKAGE_INDEX);
         });
 
-        assert_eq!(temp.package_manager.install_package("dummy-package3").unwrap(), UnableToParsePackageInfo);
+        assert_eq!(temp.package_manager.install_package("dummy-package3", false).unwrap(), UnableToParsePackageInfo);
     }
 
     #[test]
@@ -515,7 +537,7 @@ mod tests {
             std::fs::write(index_file, INSTALL_PACKAGE_INDEX);
         });
 
-        assert_eq!(temp.package_manager.install_package("dummy-package4").unwrap(), UnableToParsePackageInfo);
+        assert_eq!(temp.package_manager.install_package("dummy-package4", false).unwrap(), UnableToParsePackageInfo);
     }
 
     #[test]
@@ -525,7 +547,7 @@ mod tests {
             std::fs::write(index_file, INSTALL_PACKAGE_INDEX);
         });
 
-        assert_eq!(temp.package_manager.install_package("dummy-package").unwrap(), Installed);
+        assert_eq!(temp.package_manager.install_package("dummy-package", false).unwrap(), Installed);
         assert!(temp.package_dir.path().join("dummy-package").exists());
         assert!(temp.package_dir.path().join("dummy-package/README.md").exists());
         assert!(temp.package_dir.path().join("dummy-package/package.yml").exists());
@@ -571,6 +593,7 @@ mod tests {
         package_version: "0.1.0"
         package_author: "Federico Terzi"
         package_repo: "https://github.com/federico-terzi/espanso-hub-core"
+        is_core: true
         ---
         "###);
 
@@ -582,7 +605,9 @@ mod tests {
             version: "0.1.0".to_string(),
             repo: "https://github.com/federico-terzi/espanso-hub-core".to_string(),
             desc: "Include Italian accents substitutions to espanso.".to_string(),
-            author: "Federico Terzi".to_string()
+            author: "Federico Terzi".to_string(),
+            original_repo: "https://github.com/federico-terzi/espanso-hub-core".to_string(),
+            is_core: true,
         };
 
         assert_eq!(package, target_package);
@@ -599,6 +624,7 @@ mod tests {
         package_version:"0.1.0"
         package_author:Federico Terzi
         package_repo: "https://github.com/federico-terzi/espanso-hub-core"
+        is_core: true
         ---
         Readme text
         "###);
@@ -611,7 +637,9 @@ mod tests {
             version: "0.1.0".to_string(),
             repo: "https://github.com/federico-terzi/espanso-hub-core".to_string(),
             desc: "Include Italian accents substitutions to espanso.".to_string(),
-            author: "Federico Terzi".to_string()
+            author: "Federico Terzi".to_string(),
+            original_repo: "https://github.com/federico-terzi/espanso-hub-core".to_string(),
+            is_core: true,
         };
 
         assert_eq!(package, target_package);
diff --git a/src/package/mod.rs b/src/package/mod.rs
index 78ecaf1..c33a3bd 100644
--- a/src/package/mod.rs
+++ b/src/package/mod.rs
@@ -31,7 +31,7 @@ pub trait PackageManager {
 
     fn get_package(&self, name: &str) -> Option<Package>;
 
-    fn install_package(&self, name: &str) -> Result<InstallResult, Box<dyn Error>>;
+    fn install_package(&self, name: &str, allow_external: bool) -> Result<InstallResult, Box<dyn Error>>;
     fn install_package_from_repo(&self, name: &str, repo_url: &str) -> Result<InstallResult, Box<dyn Error>>;
 
     fn remove_package(&self, name: &str) -> Result<RemoveResult, Box<dyn Error>>;
@@ -50,9 +50,17 @@ pub struct Package {
     pub version: String,
     pub repo: String,
     pub desc: String,
-    pub author: String
+    pub author: String,
+
+    #[serde(default = "default_is_core")]
+    pub is_core: bool,
+    #[serde(default = "default_original_repo")]
+    pub original_repo: String,
 }
 
+fn default_is_core() -> bool {false}
+fn default_original_repo() -> String {"".to_owned()}
+
 #[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
 pub struct PackageIndex {
     #[serde(rename = "lastUpdate")]
@@ -75,7 +83,8 @@ pub enum InstallResult {
     UnableToParsePackageInfo,
     MissingPackageVersion,
     AlreadyInstalled,
-    Installed
+    Installed,
+    BlockedExternalPackage(String)
 }
 
 #[derive(Clone, Debug, PartialEq)]
diff --git a/src/res/test/get_package_index.json b/src/res/test/get_package_index.json
index 7512f40..428ed4e 100644
--- a/src/res/test/get_package_index.json
+++ b/src/res/test/get_package_index.json
@@ -8,7 +8,8 @@
             "version": "0.1.0",
             "repo": "https://github.com/federico-terzi/espanso-hub-core",
             "desc": "A package to include some basic emojis in espanso.",
-            "author": "Federico Terzi"
+            "author": "Federico Terzi",
+            "is_core": true
 
         },
 
@@ -19,7 +20,8 @@
             "version": "0.1.0",
             "repo": "https://github.com/federico-terzi/espanso-hub-core",
             "desc": "Include Italian accents substitutions to espanso.",
-            "author": "Federico Terzi"
+            "author": "Federico Terzi",
+            "is_core": true
 
         }
 
diff --git a/src/res/test/index_without_update.json b/src/res/test/index_without_update.json
index 4746703..7d83c46 100644
--- a/src/res/test/index_without_update.json
+++ b/src/res/test/index_without_update.json
@@ -8,7 +8,8 @@
             "version": "0.1.0",
             "repo": "https://github.com/federico-terzi/espanso-hub-core",
             "desc": "A package to include some basic emojis in espanso.",
-            "author": "Federico Terzi"
+            "author": "Federico Terzi",
+            "is_core": true
 
         },
 
@@ -19,7 +20,8 @@
             "version": "0.1.0",
             "repo": "https://github.com/federico-terzi/espanso-hub-core",
             "desc": "Include Italian accents substitutions to espanso.",
-            "author": "Federico Terzi"
+            "author": "Federico Terzi",
+            "is_core": true
 
         }
 
diff --git a/src/res/test/install_package_index.json b/src/res/test/install_package_index.json
index c9b1e62..63222f7 100644
--- a/src/res/test/install_package_index.json
+++ b/src/res/test/install_package_index.json
@@ -8,8 +8,8 @@
             "version": "0.1.0",
             "repo": "https://github.com/federico-terzi/espanso-hub-core",
             "desc": "Dummy package",
-            "author": "Federico Terzi"
-
+            "author": "Federico Terzi",
+            "is_core": true
         },
 
         {
@@ -18,7 +18,8 @@
             "version": "9.9.9",
             "repo": "https://github.com/federico-terzi/espanso-hub-core",
             "desc": "Dummy package",
-            "author": "Federico Terzi"
+            "author": "Federico Terzi",
+            "is_core": true
 
         },
 
@@ -28,7 +29,8 @@
             "version": "0.1.0",
             "repo": "https://github.com/federico-terzi/espanso-hub-core",
             "desc": "Dummy package",
-            "author": "Federico Terzi"
+            "author": "Federico Terzi",
+            "is_core": true
 
         },
 
@@ -38,7 +40,8 @@
             "version": "0.1.0",
             "repo": "https://github.com/federico-terzi/espanso-hub-core",
             "desc": "Dummy package",
-            "author": "Federico Terzi"
+            "author": "Federico Terzi",
+            "is_core": true
 
         },
 
@@ -49,7 +52,8 @@
             "version": "0.1.0",
             "repo": "https://github.com/federico-terzi/espanso-hub-core",
             "desc": "Include Italian accents substitutions to espanso.",
-            "author": "Federico Terzi"
+            "author": "Federico Terzi",
+            "is_core": true
 
         },
 
@@ -59,7 +63,8 @@
             "version": "0.1.0",
             "repo": "https://github.com/federico-terzi/espanso-hub-core",
             "desc": "Package that does not exist in the repo",
-            "author": "Federico Terzi"
+            "author": "Federico Terzi",
+            "is_core": true
 
         }
     ]}
\ No newline at end of file
diff --git a/src/res/test/outdated_index.json b/src/res/test/outdated_index.json
index 7512f40..428ed4e 100644
--- a/src/res/test/outdated_index.json
+++ b/src/res/test/outdated_index.json
@@ -8,7 +8,8 @@
             "version": "0.1.0",
             "repo": "https://github.com/federico-terzi/espanso-hub-core",
             "desc": "A package to include some basic emojis in espanso.",
-            "author": "Federico Terzi"
+            "author": "Federico Terzi",
+            "is_core": true
 
         },
 
@@ -19,7 +20,8 @@
             "version": "0.1.0",
             "repo": "https://github.com/federico-terzi/espanso-hub-core",
             "desc": "Include Italian accents substitutions to espanso.",
-            "author": "Federico Terzi"
+            "author": "Federico Terzi",
+            "is_core": true
 
         }