diff --git a/backend/tests/test_codablock.c b/backend/tests/test_codablock.c
new file mode 100644
index 00000000..a9503895
--- /dev/null
+++ b/backend/tests/test_codablock.c
@@ -0,0 +1,117 @@
+/*
+    libzint - the open source barcode library
+    Copyright (C) 2008-2019 Robin Stuart <rstuart114@gmail.com>
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+    3. Neither the name of the project nor the names of its contributors
+       may be used to endorse or promote products derived from this software
+       without specific prior written permission.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+ */
+/* vim: set ts=4 sw=4 et : */
+
+#include "testcommon.h"
+
+static void test_options(void)
+{
+    testStart("");
+
+    int ret;
+    struct item {
+        unsigned char* data;
+        int option_1;
+        int option_2;
+        int ret;
+        char* comment;
+    };
+    // s/\/\*[ 0-9]*\*\//\=printf("\/*%3d*\/", line(".") - line("'<"))
+    struct item data[] = {
+        /*  0*/ { "é", -1, -1, 0, "" },
+    };
+    int data_size = sizeof(data) / sizeof(struct item);
+
+    for (int i = 0; i < data_size; i++) {
+
+        struct zint_symbol* symbol = ZBarcode_Create();
+        assert_nonnull(symbol, "Symbol not created\n");
+
+        symbol->symbology = BARCODE_CODABLOCKF;
+        symbol->option_1 = data[i].option_1;
+        symbol->option_2 = data[i].option_2;
+
+        int length = strlen(data[i].data);
+
+        ret = ZBarcode_Encode(symbol, data[i].data, length);
+        assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d\n", i, ret, data[i].ret);
+
+        ZBarcode_Delete(symbol);
+    }
+
+    testFinish();
+}
+
+// #181 Christian Hartlage OSS-Fuzz
+static void test_fuzz(void)
+{
+    testStart("");
+
+    int ret;
+    struct item {
+        unsigned char* data;
+        int length;
+        int ret;
+    };
+    // s/\/\*[ 0-9]*\*\//\=printf("\/*%3d*\/", line(".") - line("'<"))
+    struct item data[] = {
+        /*  0*/ { "\034\034I", 3, 0 },
+    };
+    int data_size = sizeof(data) / sizeof(struct item);
+
+    for (int i = 0; i < data_size; i++) {
+
+        struct zint_symbol* symbol = ZBarcode_Create();
+        assert_nonnull(symbol, "Symbol not created\n");
+
+        symbol->symbology = BARCODE_CODABLOCKF;
+        int length = data[i].length;
+        if (length == -1) {
+            length = strlen(data[i].data);
+        }
+
+        ret = ZBarcode_Encode(symbol, data[i].data, length);
+        assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
+
+        ZBarcode_Delete(symbol);
+    }
+
+    testFinish();
+}
+
+int main()
+{
+    test_options();
+    test_fuzz();
+
+    testReport();
+
+    return 0;
+}