diff --git a/lib/client.js b/lib/client.js
index <HASH>..<HASH> 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -95,6 +95,8 @@ extend(Raven.prototype, {
   },
 
   install: function install(opts, cb) {
+    if (this.installed) return this;
+
     if (typeof opts === 'function') {
       cb = opts;
     }
@@ -110,6 +112,8 @@ extend(Raven.prototype, {
       }
     }
 
+    this.installed = true;
+
     return this;
   },
 
@@ -386,6 +390,8 @@ extend(Raven.prototype, {
   },
 
   captureBreadcrumb: function (breadcrumb) {
+    if (!this.installed) return;
+
     breadcrumb = extend({
       timestamp: +new Date / 1000
     }, breadcrumb);
Add installed flag to avoid capturing console breadcrumbs prematurely