diff --git a/src/isomorphic/classic/types/ReactPropTypes.js b/src/isomorphic/classic/types/ReactPropTypes.js
index 6a96fe7ca2b2f..4016a206bc64c 100644
--- a/src/isomorphic/classic/types/ReactPropTypes.js
+++ b/src/isomorphic/classic/types/ReactPropTypes.js
@@ -146,8 +146,7 @@ function createArrayOfTypeChecker(typeChecker) {
   function validate(props, propName, componentName, location, propFullName) {
     if (typeof typeChecker !== 'function') {
       return new Error(
-        `Invalid argument \`${propFullName}\` of type ` +
-        `\`${typeof typeChecker}\` supplied to \`${componentName}\`, expected valid PropType.`
+        `Invalid argument \`${propFullName}\` supplied to \`${componentName}\`, expected valid PropType.`
       );
     }
     var propValue = props[propName];
@@ -238,8 +237,7 @@ function createObjectOfTypeChecker(typeChecker) {
   function validate(props, propName, componentName, location, propFullName) {
     if (typeof typeChecker !== 'function') {
       return new Error(
-        `Invalid argument \`${propFullName}\` of type ` +
-        `\`${typeof typeChecker}\` supplied to \`${componentName}\`, expected valid PropType.`
+        `Invalid argument \`${propFullName}\` supplied to \`${componentName}\`, expected valid PropType.`
       );
     }
     var propValue = props[propName];
diff --git a/src/isomorphic/classic/types/__tests__/ReactPropTypes-test.js b/src/isomorphic/classic/types/__tests__/ReactPropTypes-test.js
index 6ae4c93d83aac..1b6512c16892c 100644
--- a/src/isomorphic/classic/types/__tests__/ReactPropTypes-test.js
+++ b/src/isomorphic/classic/types/__tests__/ReactPropTypes-test.js
@@ -142,7 +142,7 @@ describe('ReactPropTypes', function() {
       typeCheckFail(
         PropTypes.arrayOf({ foo: PropTypes.string }),
         { foo: 'bar' },
-        'Invalid argument `testProp` of type `object` supplied to `testComponent`, expected valid PropType.'
+        'Invalid argument `testProp` supplied to `testComponent`, expected valid PropType.'
       );
     });
 
@@ -473,7 +473,7 @@ describe('ReactPropTypes', function() {
       typeCheckFail(
         PropTypes.objectOf({ foo: PropTypes.string }),
         { foo: 'bar' },
-        'Invalid argument `testProp` of type `object` supplied to `testComponent`, expected valid PropType.'
+        'Invalid argument `testProp` supplied to `testComponent`, expected valid PropType.'
       );
     });