diff --git a/objectivec/GPBMessage.m b/objectivec/GPBMessage.m
index b29540a30f..0bdf4bb8a7 100644
--- a/objectivec/GPBMessage.m
+++ b/objectivec/GPBMessage.m
@@ -1996,9 +1996,12 @@ static GPBUnknownFieldSet *GetOrMakeUnknownFields(GPBMessage *self) {
 
 - (void)mergeFromData:(NSData *)data extensionRegistry:(id<GPBExtensionRegistry>)extensionRegistry {
   GPBCodedInputStream *input = [[GPBCodedInputStream alloc] initWithData:data];
-  [self mergeFromCodedInputStream:input extensionRegistry:extensionRegistry];
-  [input checkLastTagWas:0];
-  [input release];
+  @try {
+    [self mergeFromCodedInputStream:input extensionRegistry:extensionRegistry];
+    [input checkLastTagWas:0];
+  } @finally {
+    [input release];
+  }
 }
 
 #pragma mark - Parse From Data Support
@@ -2204,8 +2207,8 @@ static void MergeSingleFieldFromCodedInputStream(GPBMessage *self, GPBFieldDescr
         [input readMessage:message extensionRegistry:extensionRegistry];
       } else {
         GPBMessage *message = [[field.msgClass alloc] init];
-        [input readMessage:message extensionRegistry:extensionRegistry];
         GPBSetRetainedObjectIvarWithFieldPrivate(self, field, message);
+        [input readMessage:message extensionRegistry:extensionRegistry];
       }
       break;
     }
@@ -2218,8 +2221,8 @@ static void MergeSingleFieldFromCodedInputStream(GPBMessage *self, GPBFieldDescr
         [input readGroup:GPBFieldNumber(field) message:message extensionRegistry:extensionRegistry];
       } else {
         GPBMessage *message = [[field.msgClass alloc] init];
-        [input readGroup:GPBFieldNumber(field) message:message extensionRegistry:extensionRegistry];
         GPBSetRetainedObjectIvarWithFieldPrivate(self, field, message);
+        [input readGroup:GPBFieldNumber(field) message:message extensionRegistry:extensionRegistry];
       }
       break;
     }
@@ -2327,16 +2330,20 @@ static void MergeRepeatedNotPackedFieldFromCodedInputStream(
 #undef CASE_NOT_PACKED_OBJECT
     case GPBDataTypeMessage: {
       GPBMessage *message = [[field.msgClass alloc] init];
-      [input readMessage:message extensionRegistry:extensionRegistry];
       [(NSMutableArray *)genericArray addObject:message];
+      // The array will now retain message, so go ahead and release it in case
+      // -readMessage:extensionRegistry: throws so it won't be leaked.
       [message release];
+      [input readMessage:message extensionRegistry:extensionRegistry];
       break;
     }
     case GPBDataTypeGroup: {
       GPBMessage *message = [[field.msgClass alloc] init];
-      [input readGroup:GPBFieldNumber(field) message:message extensionRegistry:extensionRegistry];
       [(NSMutableArray *)genericArray addObject:message];
+      // The array will now retain message, so go ahead and release it in case
+      // -readGroup:extensionRegistry: throws so it won't be leaked.
       [message release];
+      [input readGroup:GPBFieldNumber(field) message:message extensionRegistry:extensionRegistry];
       break;
     }
     case GPBDataTypeEnum: {
diff --git a/objectivec/GPBUnknownFieldSet.m b/objectivec/GPBUnknownFieldSet.m
index 1dce738934..fd36935480 100644
--- a/objectivec/GPBUnknownFieldSet.m
+++ b/objectivec/GPBUnknownFieldSet.m
@@ -318,10 +318,12 @@ static void GPBUnknownFieldSetMergeUnknownFields(__unused const void *key, const
     }
     case GPBWireFormatStartGroup: {
       GPBUnknownFieldSet *unknownFieldSet = [[GPBUnknownFieldSet alloc] init];
-      [input readUnknownGroup:number message:unknownFieldSet];
       GPBUnknownField *field = [self mutableFieldForNumber:number create:YES];
       [field addGroup:unknownFieldSet];
+      // The field will now retain unknownFieldSet, so go ahead and release it in case
+      // -readUnknownGroup:message: throws so it won't be leaked.
       [unknownFieldSet release];
+      [input readUnknownGroup:number message:unknownFieldSet];
       return YES;
     }
     case GPBWireFormatEndGroup: