diff --git a/CMakeLists.txt b/CMakeLists.txt
index 71b5f83..f1049a5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -682,6 +682,15 @@ if(BUILD_UNIT_TEST)
                          COMMAND minizip -x -o ${EXTRA_ARGS} -d out result.zip
                          WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/test)
             endif()
+            add_test(NAME ${COMPRESS_METHOD_NAME}-append-${EXTRA_NAME}
+                    COMMAND minizip ${COMPRESS_METHOD_ARG} -a ${EXTRA_ARGS} 
+                        result.zip single.txt
+                    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/test)
+            if(NOT COMPRESS_ONLY)
+                add_test(NAME ${COMPRESS_METHOD_NAME}-append-unzip-${EXTRA_NAME}
+                            COMMAND minizip -x -o ${EXTRA_ARGS} -d out result.zip
+                            WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/test)
+            endif()
             add_test(NAME ${COMPRESS_METHOD_NAME}-erase-${EXTRA_NAME}
                     COMMAND minizip -o -e result.zip test.c test.h 
                     WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/test)
diff --git a/mz_strm_split.c b/mz_strm_split.c
index 623fb8b..bf5a1ce 100644
--- a/mz_strm_split.c
+++ b/mz_strm_split.c
@@ -223,12 +223,12 @@ int32_t mz_stream_split_open(void *stream, const char *path, int32_t mode)
     strncpy(split->path_disk, path, split->path_disk_size - 1);
     split->path_disk[split->path_disk_size - 1] = 0;
 
-    if (mode & MZ_OPEN_MODE_WRITE)
+    if ((mode & MZ_OPEN_MODE_WRITE) && ((mode & MZ_OPEN_MODE_APPEND) == 0))
     {
         number_disk = 0;
         split->current_disk = -1;
     }
-    else if (mode & MZ_OPEN_MODE_READ)
+    else
     {
         number_disk = -1;
         split->current_disk = 0;
diff --git a/mz_zip.c b/mz_zip.c
index fe8f131..58e3d6f 100644
--- a/mz_zip.c
+++ b/mz_zip.c
@@ -1372,6 +1372,12 @@ int32_t mz_zip_open(void *handle, void *stream, int32_t mode)
                 /* If no central directory, append new zip to end of file */
                 err = mz_stream_seek(zip->stream, 0, MZ_SEEK_END);
             }
+
+            if (zip->disk_number_with_cd > 0)
+            {
+                /* Move to last disk to begin appending */
+                mz_stream_set_prop_int64(zip->stream, MZ_STREAM_PROP_DISK_NUMBER, zip->disk_number_with_cd - 1);
+            }
         }
         else
         {
diff --git a/test/single.txt b/test/single.txt
new file mode 100644
index 0000000..56a6051
--- /dev/null
+++ b/test/single.txt
@@ -0,0 +1 @@
+1
\ No newline at end of file