diff --git a/slf4j-jdk-platform-logging/src/main/java/org/slf4j/jdk/SLF4JSystemLogger.java b/slf4j-jdk-platform-logging/src/main/java/org/slf4j/jdk/SLF4JSystemLogger.java
index 23f1f541..47906672 100644
--- a/slf4j-jdk-platform-logging/src/main/java/org/slf4j/jdk/SLF4JSystemLogger.java
+++ b/slf4j-jdk-platform-logging/src/main/java/org/slf4j/jdk/SLF4JSystemLogger.java
@@ -3,6 +3,7 @@ package org.slf4j.jdk;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.MissingResourceException;
 import java.util.ResourceBundle;
 
 import static java.util.Objects.requireNonNull;
@@ -53,7 +54,7 @@ class SLF4JSystemLogger implements System.Logger {
 
     @Override
     public void log(Level level, ResourceBundle bundle, String msg, Throwable thrown) {
-        String message = bundle == null ? msg : bundle.getString(msg);
+        String message = getResourceStringOrMessage(bundle, msg);
         switch(level) {
             case ALL:
                 // fall-through intended because a message is visible on all log levels
@@ -84,7 +85,7 @@ class SLF4JSystemLogger implements System.Logger {
 
     @Override
     public void log(Level level, ResourceBundle bundle, String format, Object... params) {
-        String message = bundle == null ? format : bundle.getString(format);
+        String message = getResourceStringOrMessage(bundle, format);
         switch(level) {
             case ALL:
                 // fall-through intended because a message is visible on all log levels
@@ -113,4 +114,23 @@ class SLF4JSystemLogger implements System.Logger {
         }
     }
 
+    private static String getResourceStringOrMessage(ResourceBundle bundle, String msg) {
+        if (bundle == null || msg == null)
+            return msg;
+        // ResourceBundle::getString throws:
+        //
+        //  * NullPointerException for null keys
+        //  * ClassCastException if the message is no string
+        //  * MissingResourceException if there is no message for the key
+        //
+        // Handle all of these cases here to avoid log-related exceptions from crashing the JVM.
+        try {
+            return bundle.getString(msg);
+        } catch (MissingResourceException ex) {
+            return msg;
+        } catch (ClassCastException ex) {
+            return bundle.getObject(msg).toString();
+        }
+    }
+
 }