diff --git a/dd-java-agent/agent-debugger/debugger-bootstrap/src/main/java/datadog/trace/bootstrap/debugger/util/WellKnownClasses.java b/dd-java-agent/agent-debugger/debugger-bootstrap/src/main/java/datadog/trace/bootstrap/debugger/util/WellKnownClasses.java
index de4742a7512..72aa94612a8 100644
--- a/dd-java-agent/agent-debugger/debugger-bootstrap/src/main/java/datadog/trace/bootstrap/debugger/util/WellKnownClasses.java
+++ b/dd-java-agent/agent-debugger/debugger-bootstrap/src/main/java/datadog/trace/bootstrap/debugger/util/WellKnownClasses.java
@@ -14,6 +14,7 @@
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.OptionalDouble;
@@ -187,6 +188,22 @@ public class WellKnownClasses {
     THROWABLE_SPECIAL_FIELDS.put("cause", ThrowableFields::cause);
   }
 
+  private static final List<String> SAFE_COLLECTION_PACKAGES =
+      Arrays.asList(
+          "java.", // JDK base module
+          "com.google.protobuf.", // Google ProtoBuf
+          "com.google.common.collect.", // Google Guava
+          "it.unimi.dsi.fastutil." // fastutil
+          );
+
+  private static final List<String> SAFE_MAP_PACKAGES =
+      Arrays.asList(
+          "java.", // JDK base module
+          "com.google.protobuf.", // Google ProtoBuf
+          "com.google.common.collect.", // Google Guava
+          "it.unimi.dsi.fastutil." // fastutil
+          );
+
   /**
    * @return true if type is a final class and toString implementation is well known and side effect
    *     free
@@ -207,13 +224,10 @@ public static boolean isToStringSafe(String concreteType) {
   /** @return true if collection implementation is safe to call (only in-memory) */
   public static boolean isSafe(Collection<?> collection) {
     String className = collection.getClass().getTypeName();
-    if (className.startsWith("java.")) {
-      // All Collection implementations from JDK base module are considered as safe
-      return true;
-    }
-    if (className.startsWith("com.google.protobuf.")) {
-      // All Collection implementations from Google ProtoBuf are considered as safe
-      return true;
+    for (String safePackage : SAFE_COLLECTION_PACKAGES) {
+      if (className.startsWith(safePackage)) {
+        return true;
+      }
     }
     return false;
   }
@@ -221,13 +235,10 @@ public static boolean isSafe(Collection<?> collection) {
   /** @return true if map implementation is safe to call (only in-memory) */
   public static boolean isSafe(Map<?, ?> map) {
     String className = map.getClass().getTypeName();
-    if (className.startsWith("java.")) {
-      // All Map implementations from JDK base module are considered as safe
-      return true;
-    }
-    if (className.startsWith("com.google.protobuf.")) {
-      // All Map implementations from Google ProtoBuf are considered as safe
-      return true;
+    for (String safePackage : SAFE_MAP_PACKAGES) {
+      if (className.startsWith(safePackage)) {
+        return true;
+      }
     }
     return false;
   }