diff --git a/backend/tests/test_composite.c b/backend/tests/test_composite.c
index 790e545a..20a83576 100644
--- a/backend/tests/test_composite.c
+++ b/backend/tests/test_composite.c
@@ -1610,6 +1610,53 @@ static void test_encodation_11(void)
     testFinish();
 }
 
+// #181 Christian Hartlage OSS-Fuzz
+static void test_fuzz(void)
+{
+    testStart("");
+
+    int ret;
+    struct item {
+        int symbology;
+        unsigned char* data;
+        int length;
+        unsigned char* composite;
+        int ret;
+    };
+    // s/\/\*[ 0-9]*\*\//\=printf("\/*%2d*\/", line(".") - line("'<"))
+    struct item data[] = {
+        /* 0*/ { BARCODE_EANX_CC, "+123456789012345678", -1, "[21]A12345678", ZINT_ERROR_TOO_LONG },
+        /* 1*/ { BARCODE_UPCA_CC, "+123456789012345678", -1, "[21]A12345678", ZINT_ERROR_TOO_LONG },
+        /* 2*/ { BARCODE_UPCE_CC, "+123456789012345678", -1, "[21]A12345678", ZINT_ERROR_TOO_LONG },
+        /* 3*/ { BARCODE_EANX_CC, "+12345", -1, "[21]A12345678", 0 },
+        /* 4*/ { BARCODE_EANX_CC, "+123456", -1, "[21]A12345678", ZINT_ERROR_TOO_LONG },
+    };
+    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 = data[i].symbology;
+        int length = data[i].length;
+        if (length == -1) {
+            length = strlen(data[i].data);
+        }
+        assert_zero(length >= 128, "i:%d length %d >= 128\n", i, length);
+        strcpy(symbol->primary, data[i].data);
+
+        int composite_length = strlen(data[i].composite);
+
+        ret = ZBarcode_Encode(symbol, data[i].composite, composite_length);
+        assert_equal(ret, data[i].ret, "i:%d ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
+
+        ZBarcode_Delete(symbol);
+    }
+
+    testFinish();
+}
+
 int main()
 {
     test_eanx_leading_zeroes();
@@ -1620,6 +1667,7 @@ int main()
     test_encodation_0();
     test_encodation_10();
     test_encodation_11();
+    test_fuzz();
 
     testReport();
 
diff --git a/backend/tests/test_upcean.c b/backend/tests/test_upcean.c
index 0999076f..f77a3d36 100644
--- a/backend/tests/test_upcean.c
+++ b/backend/tests/test_upcean.c
@@ -253,7 +253,7 @@ static void test_vector_same(void)
 }
 
 // #181 Christian Hartlage OSS-Fuzz
-static void test_eanx_fuzz(void)
+static void test_fuzz(void)
 {
     testStart("");
 
@@ -267,6 +267,15 @@ static void test_eanx_fuzz(void)
     // s/\/\*[ 0-9]*\*\//\=printf("\/*%2d*\/", line(".") - line("'<"))
     struct item data[] = {
         /* 0*/ { BARCODE_EANX, "55++15", -1, ZINT_ERROR_INVALID_DATA },
+        /* 1*/ { BARCODE_EANX, "+123456789012345678", -1, ZINT_ERROR_TOO_LONG },
+        /* 2*/ { BARCODE_EANX_CHK, "+123456789012345678", -1, ZINT_ERROR_TOO_LONG },
+        /* 3*/ { BARCODE_UPCA, "+123456789012345678", -1, ZINT_ERROR_TOO_LONG },
+        /* 4*/ { BARCODE_UPCA_CHK, "+123456789012345678", -1, ZINT_ERROR_TOO_LONG },
+        /* 5*/ { BARCODE_UPCE, "+123456789012345678", -1, ZINT_ERROR_TOO_LONG },
+        /* 6*/ { BARCODE_UPCE_CHK, "+123456789012345678", -1, ZINT_ERROR_TOO_LONG },
+        /* 7*/ { BARCODE_ISBNX, "+123456789012345678", -1, ZINT_ERROR_TOO_LONG },
+        /* 8*/ { BARCODE_EANX, "+12345", -1, 0 },
+        /* 9*/ { BARCODE_EANX, "+123456", -1, ZINT_ERROR_TOO_LONG },
     };
     int data_size = sizeof(data) / sizeof(struct item);
 
@@ -296,7 +305,7 @@ int main()
     test_upca_print();
     test_isbn();
     test_vector_same();
-    test_eanx_fuzz();
+    test_fuzz();
 
     testReport();
 
diff --git a/backend/upcean.c b/backend/upcean.c
index 2c644f48..15fac07f 100644
--- a/backend/upcean.c
+++ b/backend/upcean.c
@@ -594,6 +594,9 @@ INTERNAL void ean_leading_zeroes(struct zint_symbol *symbol, unsigned char sourc
         first_part[i + 1] = '\0';
     }
 
+    if (second_len >= 6) { /* Allow 6 (actual max 5) so as to trigger too long error */
+        second_len = 6;
+    }
     for (i = 0; i < second_len; i++) {
         second_part[i] = source[i + first_len + 1];
         second_part[i + 1] = '\0';
@@ -695,12 +698,11 @@ INTERNAL void ean_leading_zeroes(struct zint_symbol *symbol, unsigned char sourc
 
 /* splits string to parts before and after '+' parts */
 INTERNAL int eanx(struct zint_symbol *symbol, unsigned char source[], int src_len) {
-    unsigned char first_part[20] = {0}, second_part[20] = {0}, dest[1000] = {0};
+    unsigned char first_part[20] = {0}, second_part[7] = {0}, dest[1000] = {0};
     unsigned char local_source[20] = {0};
     unsigned int latch, reader, writer, with_addon;
     int error_number, i, plus_count;
 
-
     with_addon = FALSE;
     latch = FALSE;
     writer = 0;