diff --git a/android/src/main/java/org/conscrypt/Platform.java b/android/src/main/java/org/conscrypt/Platform.java
index c4e447a49..7b8feba5d 100644
--- a/android/src/main/java/org/conscrypt/Platform.java
+++ b/android/src/main/java/org/conscrypt/Platform.java
@@ -78,8 +78,8 @@
 @Internal
 final public class Platform {
     private static final String TAG = "Conscrypt";
-    static boolean DEPRECATED_TLS_V1 = true;
-    static boolean ENABLED_TLS_V1 = false;
+    private static boolean DEPRECATED_TLS_V1 = true;
+    private static boolean ENABLED_TLS_V1 = false;
     private static boolean FILTERED_TLS_V1 = true;
 
     private static Method m_getCurveName;
@@ -95,7 +95,7 @@ final public class Platform {
 
     private Platform() {}
 
-    public static void setup(boolean deprecatedTlsV1, boolean enabledTlsV1) {
+    public static synchronized void setup(boolean deprecatedTlsV1, boolean enabledTlsV1) {
         DEPRECATED_TLS_V1 = deprecatedTlsV1;
         ENABLED_TLS_V1 = enabledTlsV1;
         FILTERED_TLS_V1 = !enabledTlsV1;
@@ -966,15 +966,15 @@ public static boolean isJavaxCertificateSupported() {
         return true;
     }
 
-    public static boolean isTlsV1Deprecated() {
+    public static synchronized boolean isTlsV1Deprecated() {
         return DEPRECATED_TLS_V1;
     }
 
-    public static boolean isTlsV1Filtered() {
+    public static synchronized boolean isTlsV1Filtered() {
         return FILTERED_TLS_V1;
     }
 
-    public static boolean isTlsV1Supported() {
+    public static synchronized boolean isTlsV1Supported() {
         return ENABLED_TLS_V1;
     }
     public static boolean isPakeSupported() {
diff --git a/common/src/main/java/org/conscrypt/OpenSSLProvider.java b/common/src/main/java/org/conscrypt/OpenSSLProvider.java
index 988578f7b..e3a158073 100644
--- a/common/src/main/java/org/conscrypt/OpenSSLProvider.java
+++ b/common/src/main/java/org/conscrypt/OpenSSLProvider.java
@@ -52,13 +52,13 @@ public OpenSSLProvider() {
     @SuppressWarnings("deprecation")
     public OpenSSLProvider(String providerName) {
         this(providerName, Platform.provideTrustManagerByDefault(), "TLSv1.3",
-            Platform.DEPRECATED_TLS_V1, Platform.ENABLED_TLS_V1);
+                Platform.isTlsV1Deprecated(), Platform.isTlsV1Supported());
     }
 
     OpenSSLProvider(String providerName, boolean includeTrustManager,
             String defaultTlsProtocol) {
-        this(providerName, includeTrustManager, defaultTlsProtocol,
-            Platform.DEPRECATED_TLS_V1, Platform.ENABLED_TLS_V1);
+        this(providerName, includeTrustManager, defaultTlsProtocol, Platform.isTlsV1Deprecated(),
+                Platform.isTlsV1Supported());
     }
 
     OpenSSLProvider(String providerName, boolean includeTrustManager,
diff --git a/openjdk/src/main/java/org/conscrypt/Platform.java b/openjdk/src/main/java/org/conscrypt/Platform.java
index 269d284b3..1ca6f4958 100644
--- a/openjdk/src/main/java/org/conscrypt/Platform.java
+++ b/openjdk/src/main/java/org/conscrypt/Platform.java
@@ -97,8 +97,8 @@
 final public class Platform {
     private static final int JAVA_VERSION = javaVersion0();
     private static final Method GET_CURVE_NAME_METHOD;
-    static boolean DEPRECATED_TLS_V1 = true;
-    static boolean ENABLED_TLS_V1 = false;
+    private static boolean DEPRECATED_TLS_V1 = true;
+    private static boolean ENABLED_TLS_V1 = false;
     private static boolean FILTERED_TLS_V1 = false;
 
     static {
@@ -115,14 +115,13 @@ final public class Platform {
 
     private Platform() {}
 
-    public static void setup(boolean deprecatedTlsV1, boolean enabledTlsV1) {
+    public static synchronized void setup(boolean deprecatedTlsV1, boolean enabledTlsV1) {
         DEPRECATED_TLS_V1 = deprecatedTlsV1;
         ENABLED_TLS_V1 = enabledTlsV1;
         FILTERED_TLS_V1 = !enabledTlsV1;
         NativeCrypto.setTlsV1DeprecationStatus(DEPRECATED_TLS_V1, ENABLED_TLS_V1);
     }
 
-
     /**
      * Approximates the behavior of File.createTempFile without depending on SecureRandom.
      */
@@ -850,15 +849,15 @@ public static boolean isJavaxCertificateSupported() {
         return JAVA_VERSION < 15;
     }
 
-    public static boolean isTlsV1Deprecated() {
+    public static synchronized boolean isTlsV1Deprecated() {
         return DEPRECATED_TLS_V1;
     }
 
-    public static boolean isTlsV1Filtered() {
+    public static synchronized boolean isTlsV1Filtered() {
         return FILTERED_TLS_V1;
     }
 
-    public static boolean isTlsV1Supported() {
+    public static synchronized boolean isTlsV1Supported() {
         return ENABLED_TLS_V1;
     }
 
diff --git a/platform/src/main/java/org/conscrypt/Platform.java b/platform/src/main/java/org/conscrypt/Platform.java
index e98ece7c3..edcf20211 100644
--- a/platform/src/main/java/org/conscrypt/Platform.java
+++ b/platform/src/main/java/org/conscrypt/Platform.java
@@ -85,8 +85,8 @@
 @Internal
 final public class Platform {
     private static class NoPreloadHolder { public static final Platform MAPPER = new Platform(); }
-    static boolean DEPRECATED_TLS_V1 = true;
-    static boolean ENABLED_TLS_V1 = false;
+    private static boolean DEPRECATED_TLS_V1 = true;
+    private static boolean ENABLED_TLS_V1 = false;
     private static boolean FILTERED_TLS_V1 = true;
 
     static {
@@ -96,7 +96,7 @@ private static class NoPreloadHolder { public static final Platform MAPPER = new
     /**
      * Runs all the setup for the platform that only needs to run once.
      */
-    public static void setup(boolean deprecatedTlsV1, boolean enabledTlsV1) {
+    public static synchronized void setup(boolean deprecatedTlsV1, boolean enabledTlsV1) {
         DEPRECATED_TLS_V1 = deprecatedTlsV1;
         ENABLED_TLS_V1 = enabledTlsV1;
         FILTERED_TLS_V1 = !enabledTlsV1;
@@ -576,11 +576,11 @@ public static boolean isJavaxCertificateSupported() {
         return true;
     }
 
-    public static boolean isTlsV1Deprecated() {
+    public static synchronized boolean isTlsV1Deprecated() {
         return DEPRECATED_TLS_V1;
     }
 
-    public static boolean isTlsV1Filtered() {
+    public static synchronized boolean isTlsV1Filtered() {
         Object targetSdkVersion = getTargetSdkVersion();
         if ((targetSdkVersion != null) && ((int) targetSdkVersion > 35)
                && ((int) targetSdkVersion < 100))
@@ -588,7 +588,7 @@ public static boolean isTlsV1Filtered() {
         return FILTERED_TLS_V1;
     }
 
-    public static boolean isTlsV1Supported() {
+    public static synchronized boolean isTlsV1Supported() {
         return ENABLED_TLS_V1;
     }