diff --git a/schema_salad/java/main_utils/YamlUtils.java b/schema_salad/java/main_utils/YamlUtils.java
index 0ad2ce0a..cce5062f 100644
--- a/schema_salad/java/main_utils/YamlUtils.java
+++ b/schema_salad/java/main_utils/YamlUtils.java
@@ -1,21 +1,175 @@
 package ${package}.utils;
 
+import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import org.yaml.snakeyaml.Yaml;
-import org.yaml.snakeyaml.constructor.SafeConstructor;
+import java.util.Objects;
+import java.util.regex.Pattern;
+
+import org.snakeyaml.engine.v2.api.Load;
+import org.snakeyaml.engine.v2.api.LoadSettings;
+import org.snakeyaml.engine.v2.nodes.Tag;
+import org.snakeyaml.engine.v2.resolver.ScalarResolver;
+
+// Copied from org.snakeyaml.engine.v2.resolver.ResolverTuple because it was marked non-public
+/**
+ * Copyright (c) 2018, http://www.snakeyaml.org
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+final class ResolverTuple {
+	private final Tag tag;
+	private final Pattern regexp;
+
+	public ResolverTuple(Tag tag, Pattern regexp) {
+		Objects.requireNonNull(tag, "Tag must be provided");
+		Objects.requireNonNull(regexp, "regexp must be provided");
+		this.tag = tag;
+		this.regexp = regexp;
+	}
+
+	public Tag getTag() {
+		return tag;
+	}
+
+	public Pattern getRegexp() {
+		return regexp;
+	}
+
+	@Override
+	public String toString() {
+		return "Tuple tag=" + tag + " regexp=" + regexp;
+	}
+}
+
+
+// Adapted from org.snakeyaml.engine.v2.resolver.JsonScalarResolver
+// Not guaranteed to be complete coverage of the YAML 1.2 Core Schema
+// 2021-02-03 Supports 'True'/'False'/'TRUE','FALSE' as boolean; 'Null', 'NULL', an '~' as null
+/**
+ * Copyright (c) 2018, http://www.snakeyaml.org
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+class CoreScalarResolver implements ScalarResolver {
+	public final Pattern BOOL = Pattern.compile("^(?:true|false|True|False|TRUE|FALSE)$");
+	public static final Pattern FLOAT = Pattern
+			.compile("^(-?(0?\\.[0-9]+|[1-9][0-9]*(\\.[0-9]*)?)(e[-+]?[0-9]+)?)|-?\\.(?:inf)|\\.(?:nan)$"); // NOSONAR
+	public static final Pattern INT = Pattern.compile("^(?:-?(?:0|[1-9][0-9]*))$");
+	public static final Pattern NULL = Pattern.compile("^(?:null|Null|NULL|~)$");
+	public static final Pattern EMPTY = Pattern.compile("^$");
+
+	public static final Pattern ENV_FORMAT = Pattern
+			.compile("^\\$\\{\\s*((?<name>\\w+)((?<separator>:?(-|\\?))(?<value>\\w+)?)?)\\s*\\}$");
+
+	protected Map<Character, List<ResolverTuple>> yamlImplicitResolvers = new HashMap<Character, List<ResolverTuple>>();
+
+	public void addImplicitResolver(Tag tag, Pattern regexp, String first) {
+		if (first == null) {
+			List<ResolverTuple> curr = yamlImplicitResolvers.computeIfAbsent(null, c -> new ArrayList<ResolverTuple>());
+			curr.add(new ResolverTuple(tag, regexp));
+		} else {
+			char[] chrs = first.toCharArray();
+			for (int i = 0, j = chrs.length; i < j; i++) {
+				Character theC = Character.valueOf(chrs[i]);
+				if (theC == 0) {
+					// special case: for null
+					theC = null;
+				}
+				List<ResolverTuple> curr = yamlImplicitResolvers.get(theC);
+				if (curr == null) {
+					curr = new ArrayList<ResolverTuple>();
+					yamlImplicitResolvers.put(theC, curr);
+				}
+				curr.add(new ResolverTuple(tag, regexp));
+			}
+		}
+	}
+
+	protected void addImplicitResolvers() {
+		addImplicitResolver(Tag.NULL, EMPTY, null);
+		addImplicitResolver(Tag.BOOL, BOOL, "tfTF");
+		/*
+		 * INT must be before FLOAT because the regular expression for FLOAT matches INT
+		 * (see issue 130) http://code.google.com/p/snakeyaml/issues/detail?id=130
+		 */
+		addImplicitResolver(Tag.INT, INT, "-0123456789");
+		addImplicitResolver(Tag.FLOAT, FLOAT, "-0123456789.");
+		addImplicitResolver(Tag.NULL, NULL, "nN~\u0000");
+		addImplicitResolver(Tag.ENV_TAG, ENV_FORMAT, "$");
+	}
+
+	public CoreScalarResolver() {
+		addImplicitResolvers();
+	}
+
+	@Override
+	public Tag resolve(String value, Boolean implicit) {
+		if (!implicit) {
+			return Tag.STR;
+		}
+		final List<ResolverTuple> resolvers;
+		if (value.length() == 0) {
+			resolvers = yamlImplicitResolvers.get('\0');
+		} else {
+			resolvers = yamlImplicitResolvers.get(value.charAt(0));
+		}
+		if (resolvers != null) {
+			for (ResolverTuple v : resolvers) {
+				Tag tag = v.getTag();
+				Pattern regexp = v.getRegexp();
+				if (regexp.matcher(value).matches()) {
+					return tag;
+				}
+			}
+		}
+		if (yamlImplicitResolvers.containsKey(null)) {
+			for (ResolverTuple v : yamlImplicitResolvers.get(null)) {
+				Tag tag = v.getTag();
+				Pattern regexp = v.getRegexp();
+				if (regexp.matcher(value).matches()) {
+					return tag;
+				}
+			}
+		}
+		return Tag.STR;
+	}
+}
 
 public class YamlUtils {
 
-  public static Map<String, Object> mapFromString(final String text) {
-    Yaml yaml = new Yaml(new SafeConstructor());
-    final Map<String, Object> result = yaml.load(text);
-    return result;
-  }
-
-  public static List<Object> listFromString(final String text) {
-    Yaml yaml = new Yaml(new SafeConstructor());
-    final List<Object> result = yaml.load(text);
-    return result;
-  }
+	public static Map<String, Object> mapFromString(final String text) {
+		LoadSettings settings = LoadSettings.builder().setScalarResolver(new CoreScalarResolver()).build();
+		Load load = new Load(settings);
+		final Map<String, Object> result = (Map<String, Object>) load.loadFromString(text);
+		return result;
+	}
+
+	public static List<Object> listFromString(final String text) {
+		LoadSettings settings = LoadSettings.builder().setScalarResolver(new CoreScalarResolver()).build();
+		Load load = new Load(settings);
+		final List<Object> result = (List<Object>) load.loadFromString(text);
+		return result;
+	}
 }
diff --git a/schema_salad/java/pom.xml b/schema_salad/java/pom.xml
index 13c16438..4d2b7046 100644
--- a/schema_salad/java/pom.xml
+++ b/schema_salad/java/pom.xml
@@ -119,9 +119,9 @@
             <version>4.13.1</version>
         </dependency>
         <dependency>
-            <groupId>org.yaml</groupId>
-            <artifactId>snakeyaml</artifactId>
-            <version>1.24</version>
+            <groupId>org.snakeyaml</groupId>
+            <artifactId>snakeyaml-engine</artifactId>
+            <version>2.2.1</version>
         </dependency>
     </dependencies>
 </project>