diff --git a/bcprov/src/main/java/org/bouncycastle/jcajce/provider/symmetric/util/BaseBlockCipher.java b/bcprov/src/main/java/org/bouncycastle/jcajce/provider/symmetric/util/BaseBlockCipher.java
index db2f66c..d3d04db 100644
--- a/bcprov/src/main/java/org/bouncycastle/jcajce/provider/symmetric/util/BaseBlockCipher.java
+++ b/bcprov/src/main/java/org/bouncycastle/jcajce/provider/symmetric/util/BaseBlockCipher.java
@@ -454,7 +454,8 @@
         }
         */
         // END Android-removed: Unsupported modes
-        else if (modeName.startsWith("GCM"))
+        // Android-changed: Use equals instead of startsWith to not catch GCM-SIV
+        else if (modeName.equalsIgnoreCase("GCM"))
         {
             ivLength = baseEngine.getBlockSize();
             // BEGIN Android-removed: Unsupported algorithms
diff --git a/repackaged/bcprov/src/main/java/com/android/org/bouncycastle/jcajce/provider/symmetric/util/BaseBlockCipher.java b/repackaged/bcprov/src/main/java/com/android/org/bouncycastle/jcajce/provider/symmetric/util/BaseBlockCipher.java
index 5c29fae..1351477 100644
--- a/repackaged/bcprov/src/main/java/com/android/org/bouncycastle/jcajce/provider/symmetric/util/BaseBlockCipher.java
+++ b/repackaged/bcprov/src/main/java/com/android/org/bouncycastle/jcajce/provider/symmetric/util/BaseBlockCipher.java
@@ -458,7 +458,8 @@
         }
         */
         // END Android-removed: Unsupported modes
-        else if (modeName.startsWith("GCM"))
+        // Android-changed: Use equals instead of startsWith to not catch GCM-SIV
+        else if (modeName.equalsIgnoreCase("GCM"))
         {
             ivLength = baseEngine.getBlockSize();
             // BEGIN Android-removed: Unsupported algorithms