diff --git a/pgpainless-core/src/main/java/org/pgpainless/algorithm/CompressionAlgorithm.java b/pgpainless-core/src/main/java/org/pgpainless/algorithm/CompressionAlgorithm.java
index 5c2be73f..2b531f49 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/algorithm/CompressionAlgorithm.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/algorithm/CompressionAlgorithm.java
@@ -15,8 +15,8 @@
  */
 package org.pgpainless.algorithm;
 
-import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.bouncycastle.bcpg.CompressionAlgorithmTags;
 
@@ -28,7 +28,7 @@ public enum CompressionAlgorithm {
     BZIP2          (CompressionAlgorithmTags.BZIP2),
     ;
 
-    private static final Map<Integer, CompressionAlgorithm> MAP = new HashMap<>();
+    private static final Map<Integer, CompressionAlgorithm> MAP = new ConcurrentHashMap<>();
 
     static {
         for (CompressionAlgorithm c : CompressionAlgorithm.values()) {
diff --git a/pgpainless-core/src/main/java/org/pgpainless/algorithm/Feature.java b/pgpainless-core/src/main/java/org/pgpainless/algorithm/Feature.java
index d3fa5293..8bcf0369 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/algorithm/Feature.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/algorithm/Feature.java
@@ -15,8 +15,8 @@
  */
 package org.pgpainless.algorithm;
 
-import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.bouncycastle.bcpg.sig.Features;
 
@@ -31,7 +31,7 @@ public enum Feature {
     MODIFICATION_DETECTION(Features.FEATURE_MODIFICATION_DETECTION),
     ;
 
-    private static final Map<Byte, Feature> MAP = new HashMap<>();
+    private static final Map<Byte, Feature> MAP = new ConcurrentHashMap<>();
 
     static {
         for (Feature f : Feature.values()) {
diff --git a/pgpainless-core/src/main/java/org/pgpainless/algorithm/HashAlgorithm.java b/pgpainless-core/src/main/java/org/pgpainless/algorithm/HashAlgorithm.java
index 896acdde..caf2364d 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/algorithm/HashAlgorithm.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/algorithm/HashAlgorithm.java
@@ -15,8 +15,8 @@
  */
 package org.pgpainless.algorithm;
 
-import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.bouncycastle.bcpg.HashAlgorithmTags;
 
@@ -34,8 +34,8 @@ public enum HashAlgorithm {
     SHA512     (HashAlgorithmTags.SHA512),
     SHA224     (HashAlgorithmTags.SHA224),
     ;
-    //                                                         Coincidence? I don't this so...
-    private static final Map<Integer, HashAlgorithm> MAP = new HashMap<>();
+
+    private static final Map<Integer, HashAlgorithm> MAP = new ConcurrentHashMap<>();
 
     static {
         for (HashAlgorithm h : HashAlgorithm.values()) {
diff --git a/pgpainless-core/src/main/java/org/pgpainless/algorithm/PublicKeyAlgorithm.java b/pgpainless-core/src/main/java/org/pgpainless/algorithm/PublicKeyAlgorithm.java
index b598b125..8307cb91 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/algorithm/PublicKeyAlgorithm.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/algorithm/PublicKeyAlgorithm.java
@@ -15,8 +15,8 @@
  */
 package org.pgpainless.algorithm;
 
-import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.bouncycastle.bcpg.PublicKeyAlgorithmTags;
 
@@ -38,7 +38,7 @@ public enum PublicKeyAlgorithm {
     DIFFIE_HELLMAN  (PublicKeyAlgorithmTags.DIFFIE_HELLMAN),
     ;
 
-    private static final Map<Integer, PublicKeyAlgorithm> MAP = new HashMap<>();
+    private static final Map<Integer, PublicKeyAlgorithm> MAP = new ConcurrentHashMap<>();
 
     static {
         for (PublicKeyAlgorithm p : PublicKeyAlgorithm.values()) {
diff --git a/pgpainless-core/src/main/java/org/pgpainless/algorithm/SymmetricKeyAlgorithm.java b/pgpainless-core/src/main/java/org/pgpainless/algorithm/SymmetricKeyAlgorithm.java
index 36a28651..e69a8fa4 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/algorithm/SymmetricKeyAlgorithm.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/algorithm/SymmetricKeyAlgorithm.java
@@ -15,8 +15,8 @@
  */
 package org.pgpainless.algorithm;
 
-import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.bouncycastle.bcpg.SymmetricKeyAlgorithmTags;
 
@@ -42,7 +42,7 @@ public enum SymmetricKeyAlgorithm {
     CAMELLIA_256    (SymmetricKeyAlgorithmTags.CAMELLIA_256),
     ;
 
-    private static final Map<Integer, SymmetricKeyAlgorithm> MAP = new HashMap<>();
+    private static final Map<Integer, SymmetricKeyAlgorithm> MAP = new ConcurrentHashMap<>();
 
     static {
         for (SymmetricKeyAlgorithm s : SymmetricKeyAlgorithm.values()) {