diff --git a/lib/jasmine-core/jasmine.js b/lib/jasmine-core/jasmine.js
index 06c35e71..8700ca69 100644
--- a/lib/jasmine-core/jasmine.js
+++ b/lib/jasmine-core/jasmine.js
@@ -267,6 +267,10 @@ getJasmineRequireObj().base = function(j$, jasmineGlobal) {
   };
 
   j$.isError_ = function(value) {
+    if (!value) {
+      return false;
+    }
+
     if (value instanceof Error) {
       return true;
     }
@@ -275,9 +279,7 @@ getJasmineRequireObj().base = function(j$, jasmineGlobal) {
       typeof window.trustedTypes !== 'undefined'
     ) {
       return (
-        value &&
-        typeof value.stack === 'string' &&
-        typeof value.message === 'string'
+        typeof value.stack === 'string' && typeof value.message === 'string'
       );
     }
     if (value && value.constructor && value.constructor.constructor) {
diff --git a/src/core/base.js b/src/core/base.js
index 1d31d89d..89cd2b6e 100644
--- a/src/core/base.js
+++ b/src/core/base.js
@@ -99,6 +99,10 @@ getJasmineRequireObj().base = function(j$, jasmineGlobal) {
   };
 
   j$.isError_ = function(value) {
+    if (!value) {
+      return false;
+    }
+
     if (value instanceof Error) {
       return true;
     }
@@ -107,9 +111,7 @@ getJasmineRequireObj().base = function(j$, jasmineGlobal) {
       typeof window.trustedTypes !== 'undefined'
     ) {
       return (
-        value &&
-        typeof value.stack === 'string' &&
-        typeof value.message === 'string'
+        typeof value.stack === 'string' && typeof value.message === 'string'
       );
     }
     if (value && value.constructor && value.constructor.constructor) {