diff --git a/app/assets/javascripts/admin/addon/controllers/modals/admin-install-theme.js b/app/assets/javascripts/admin/addon/controllers/modals/admin-install-theme.js
index 79f47dfc696..bc6258228da 100644
--- a/app/assets/javascripts/admin/addon/controllers/modals/admin-install-theme.js
+++ b/app/assets/javascripts/admin/addon/controllers/modals/admin-install-theme.js
@@ -125,6 +125,19 @@ export default Controller.extend(ModalFunctionality, {
     return privateChecked && checkPrivate && publicKey;
   },
 
+  onClose() {
+    this.set("duplicateRemoteThemeWarning", null);
+  },
+
+  themeHasSameUrl(theme, url) {
+    const themeUrl = theme.remote_theme && theme.remote_theme.remote_url;
+    return (
+      themeUrl &&
+      url &&
+      url.replace(/\.git$/, "") === themeUrl.replace(/\.git$/, "")
+    );
+  },
+
   actions: {
     uploadLocaleFile() {
       this.set("localFile", $("#file-input")[0].files[0]);
@@ -167,6 +180,17 @@ export default Controller.extend(ModalFunctionality, {
       }
 
       if (this.remote || this.popular) {
+        const duplicate = this.themesController.model.content.find((theme) =>
+          this.themeHasSameUrl(theme, this.uploadUrl)
+        );
+        if (duplicate && !this.duplicateRemoteThemeWarning) {
+          const warning = I18n.t(
+            "admin.customize.theme.duplicate_remote_theme",
+            { name: duplicate.name }
+          );
+          this.set("duplicateRemoteThemeWarning", warning);
+          return;
+        }
         options.data = {
           remote: this.uploadUrl,
           branch: this.branch,
diff --git a/app/assets/javascripts/admin/addon/templates/modal/admin-install-theme.hbs b/app/assets/javascripts/admin/addon/templates/modal/admin-install-theme.hbs
index 053ce042a8c..bbe8e4a83a2 100644
--- a/app/assets/javascripts/admin/addon/templates/modal/admin-install-theme.hbs
+++ b/app/assets/javascripts/admin/addon/templates/modal/admin-install-theme.hbs
@@ -103,6 +103,11 @@
 
 {{#unless popular}}
   <div class="modal-footer">
+    {{#if duplicateRemoteThemeWarning}}
+      <div class="install-theme-warning">
+        ⚠️ {{duplicateRemoteThemeWarning}}
+      </div>
+    {{/if}}
     {{d-button action=(action "installTheme") disabled=installDisabled class="btn btn-primary" label=submitLabel}}
     {{d-modal-cancel close=(route-action "closeModal")}}
   </div>
diff --git a/app/assets/stylesheets/common/admin/customize-install-theme.scss b/app/assets/stylesheets/common/admin/customize-install-theme.scss
index 70e65ae6562..141365c6e6d 100644
--- a/app/assets/stylesheets/common/admin/customize-install-theme.scss
+++ b/app/assets/stylesheets/common/admin/customize-install-theme.scss
@@ -126,3 +126,7 @@
     }
   }
 }
+
+.install-theme-warning {
+  margin-bottom: 10px;
+}
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index 74ecc13e69a..80180a7aa97 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -4088,6 +4088,7 @@ en:
           install_upload: "From your device"
           install_git_repo: "From a git repository"
           install_create: "Create new"
+          duplicate_remote_theme: "The theme component “%{name}” is already installed, are you sure you want to install another copy?"
           about_theme: "About"
           license: "License"
           version: "Version:"