diff --git a/lib/unit.js b/lib/unit.js
index 06a1f66..884d223 100644
--- a/lib/unit.js
+++ b/lib/unit.js
@@ -18,7 +18,7 @@ module.exports = function(value) {
     if (code >= 48 && code <= 57) {
       containsNumber = true;
     } else if (code === exp || code === EXP) {
-      if (sciPos > -1) {
+      if (sciPos > -1 || pos === 0) {
         break;
       }
       sciPos = pos;
diff --git a/test/unit.js b/test/unit.js
index 55f989f..87279ed 100644
--- a/test/unit.js
+++ b/test/unit.js
@@ -53,6 +53,10 @@ var tests = [
   {
     fixture: "e",
     expected: false
+  },
+  {
+    fixture: "e1",
+    expected: false
   }
 ];