diff --git a/package-lock.json b/package-lock.json
index c5de9f2764f..a68c53dbe6d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -6772,9 +6772,9 @@
       "dev": true
     },
     "karma-jasmine-spec-tags": {
-      "version": "1.1.0",
-      "resolved": "https://registry.npmjs.org/karma-jasmine-spec-tags/-/karma-jasmine-spec-tags-1.1.0.tgz",
-      "integrity": "sha512-uhGYcGV1jmUSe2QZ6D/pmVehnggQaB8LCaG17EWetYJnGGu6C7LUcPkVNeMXMiewwa5V6g8RxOG8LP8Jh1ZBsQ==",
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/karma-jasmine-spec-tags/-/karma-jasmine-spec-tags-1.0.1.tgz",
+      "integrity": "sha1-Mz7WJZKSMG81Dez3f5uNxcOVQhI=",
       "dev": true
     },
     "karma-spec-reporter": {
diff --git a/package.json b/package.json
index c3494f755ba..2df682168f2 100644
--- a/package.json
+++ b/package.json
@@ -142,7 +142,7 @@
     "karma-firefox-launcher": "^1.0.1",
     "karma-ie-launcher": "^1.0.0",
     "karma-jasmine": "^1.1.2",
-    "karma-jasmine-spec-tags": "^1.1.0",
+    "karma-jasmine-spec-tags": "^1.0.1",
     "karma-spec-reporter": "0.0.32",
     "karma-verbose-reporter": "0.0.6",
     "karma-viewport": "^1.0.4",
diff --git a/src/plots/cartesian/axes.js b/src/plots/cartesian/axes.js
index cb2a114ca1f..151328a0b63 100644
--- a/src/plots/cartesian/axes.js
+++ b/src/plots/cartesian/axes.js
@@ -1317,7 +1317,14 @@ function numFormat(v, ax, fmtoverride, hover) {
         if(ax.hoverformat) tickformat = ax.hoverformat;
     }
 
-    if(tickformat) return ax._numFormat(tickformat)(v).replace(/-/g, MINUS_SIGN);
+    if(tickformat) {
+        if(tickformat === 'p') {
+            tickRound -= 2;
+            exponent = 0;
+        } else {
+            return ax._numFormat(tickformat)(v).replace(/-/g, MINUS_SIGN);
+        }
+    }
 
     // 'epsilon' - rounding increment
     var e = Math.pow(10, -tickRound) / 2;
@@ -1385,7 +1392,10 @@ function numFormat(v, ax, fmtoverride, hover) {
     // put sign back in and return
     // replace standard minus character (which is technically a hyphen)
     // with a true minus sign
-    if(isNeg) return MINUS_SIGN + v;
+    if(isNeg) v = MINUS_SIGN + v;
+
+    if(tickformat === 'p') v = (v * 100) + '%';
+
     return v;
 }
 
diff --git a/test/image/baselines/tickformat_percent.png b/test/image/baselines/tickformat_percent.png
new file mode 100644
index 00000000000..6323aa015f3
Binary files /dev/null and b/test/image/baselines/tickformat_percent.png differ
diff --git a/test/image/mocks/tickformat_percent.json b/test/image/mocks/tickformat_percent.json
new file mode 100644
index 00000000000..c9b1af45639
--- /dev/null
+++ b/test/image/mocks/tickformat_percent.json
@@ -0,0 +1,33 @@
+{
+  "data": [{
+    "y": [0, 1]
+  }, {
+    "y": [1, 0],
+    "yaxis": "y4"
+  }, {
+    "y": [0, 0.0001],
+    "yaxis": "y2"
+  }, {
+    "y": [0.0001, 0],
+    "yaxis": "y5"
+  }, {
+    "y": [0, 1.000121321321321],
+    "yaxis": "y3"
+  }, {
+    "y": [1.0001321321321121, 0],
+    "yaxis": "y6"
+  }],
+  "layout": {
+    "grid": {"rows": 3, "columns": 1},
+    "title": {"text": "left: 'p' tickformat | right dflt tickformat"},
+    "showlegend": false,
+
+    "yaxis": {"tickformat": "p"},
+    "yaxis2": {"tickformat": "p"},
+    "yaxis3": {"tickformat": "p"},
+
+    "yaxis4": {"overlaying": "y", "side": "right"},
+    "yaxis5": {"overlaying": "y2", "side": "right"},
+    "yaxis6": {"overlaying": "y3", "side": "right"}
+  }
+}