diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6482821b..601408ab 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,9 @@
 
 ### Patches
 * Detects stuck AMD Ryzen RDRAND and correctly treats as an error
+* `KeyPairGenerator` for "EC" keys when initialized with a `int` always uses "secp*r1" curves now.
+  This matches the behavior of SunEC.
+  **This changes the curves selected for 192 and 256 from secp192k1 to secp192r1/P-192 and secp256k1 to secp256r1/P-256 respectively.**
 
 ### Maintenance
 * Add prefix to test output lines indicating if suite will fail.
diff --git a/src/com/amazon/corretto/crypto/provider/EcGen.java b/src/com/amazon/corretto/crypto/provider/EcGen.java
index d55f17ae..2719ce46 100644
--- a/src/com/amazon/corretto/crypto/provider/EcGen.java
+++ b/src/com/amazon/corretto/crypto/provider/EcGen.java
@@ -166,12 +166,7 @@ private static byte[] encodeSpec(final AlgorithmParameterSpec spec) {
     public void initialize(final int keysize, final SecureRandom random)
             throws InvalidParameterException {
         try {
-            final String curveName;
-            if (keysize == 192 || keysize == 256) {
-                curveName = "secp" + keysize + "k1";
-            } else {
-                curveName = "secp" + keysize + "r1";
-            }
+            final String curveName = "secp" + keysize + "r1";
             initialize(new ECGenParameterSpec(curveName), random);
         } catch (final InvalidAlgorithmParameterException ex) {
             throw new InvalidParameterException(ex.getMessage());
diff --git a/tst/com/amazon/corretto/crypto/provider/test/EcGenTest.java b/tst/com/amazon/corretto/crypto/provider/test/EcGenTest.java
index 4e706886..6eeea9aa 100644
--- a/tst/com/amazon/corretto/crypto/provider/test/EcGenTest.java
+++ b/tst/com/amazon/corretto/crypto/provider/test/EcGenTest.java
@@ -4,13 +4,12 @@
 package com.amazon.corretto.crypto.provider.test;
 
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
 import java.math.BigInteger;
 import java.security.GeneralSecurityException;
 import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidParameterException;
 import java.security.Key;
 import java.security.KeyFactory;
 import java.security.KeyPair;
@@ -42,6 +41,7 @@
 import org.junit.Test;
 
 public class EcGenTest {
+    public static final int[] KNOWN_SIZES = {192, 224, 256, 384, 521};
     public static final String[][] KNOWN_CURVES = new String[][] {
             // Prime Curves
             new String[]{"secp112r1", "1.3.132.0.6"},
@@ -170,6 +170,28 @@ public void knownCurves() throws GeneralSecurityException {
         }
     }
 
+    @Test
+    public void knownSizes() throws GeneralSecurityException {
+        TestUtil.assumeMinimumVersion("1.2.0", nativeGen.getProvider());
+        for (int keysize : KNOWN_SIZES) {
+            nativeGen.initialize(keysize);
+            jceGen.initialize(keysize);
+
+            final KeyPair nativePair = nativeGen.generateKeyPair();
+            final KeyPair jcePair = jceGen.generateKeyPair();
+
+            final ECParameterSpec jceParams = ((ECPublicKey) jcePair.getPublic()).getParams();
+            final ECParameterSpec nativeParams = ((ECPublicKey) nativePair.getPublic()).getParams();
+            assertECEquals(Integer.toString(keysize), jceParams, nativeParams);
+        }
+    }
+
+    @Test
+    public void unknownSize() throws GeneralSecurityException {
+        TestUtil.assertThrows(InvalidParameterException.class,
+                () -> nativeGen.initialize(13));
+    }
+
     @Test
     public void explicitCurve() throws GeneralSecurityException {
         jceGen.initialize(EXPLICIT_CURVE);
diff --git a/tst/com/amazon/corretto/crypto/provider/test/integration/test_CA.jks b/tst/com/amazon/corretto/crypto/provider/test/integration/test_CA.jks
index 63071c11..29cbe642 100644
Binary files a/tst/com/amazon/corretto/crypto/provider/test/integration/test_CA.jks and b/tst/com/amazon/corretto/crypto/provider/test/integration/test_CA.jks differ
diff --git a/tst/com/amazon/corretto/crypto/provider/test/integration/test_private_keys.jks b/tst/com/amazon/corretto/crypto/provider/test/integration/test_private_keys.jks
index 2d9afe22..3ef10d64 100644
Binary files a/tst/com/amazon/corretto/crypto/provider/test/integration/test_private_keys.jks and b/tst/com/amazon/corretto/crypto/provider/test/integration/test_private_keys.jks differ