diff --git a/lib/fort.c b/lib/fort.c
index 57c916f..570d784 100644
--- a/lib/fort.c
+++ b/lib/fort.c
@@ -176,7 +176,7 @@ struct conv_context {
     union {
         char *buf;
         wchar_t *wbuf;
-    };
+    } u;
     size_t raw_avail;
     struct fort_context *cntx;
     enum str_buf_type b_type;
@@ -3072,7 +3072,7 @@ const void *ft_to_string_impl(const ft_table_t *table, enum str_buf_type b_type)
 
     conv_context_t cntx;
     cntx.buf_origin = buffer;
-    cntx.buf = buffer;
+    cntx.u.buf = buffer;
     cntx.raw_avail = string_buffer_raw_capacity(table->conv_buffer);
     cntx.cntx = &context;
     cntx.b_type = b_type;
@@ -3635,9 +3635,9 @@ int snprint_n_strings_impl(char *buf, size_t length, size_t n, const char *str)
 static
 int snprint_n_strings(conv_context_t *cntx, size_t n, const char *str)
 {
-    int w = snprint_n_strings_impl(cntx->buf, cntx->raw_avail, n, str);
+    int w = snprint_n_strings_impl(cntx->u.buf, cntx->raw_avail, n, str);
     if (w >= 0) {
-        cntx->buf += w;
+        cntx->u.buf += w;
         cntx->raw_avail -= w;
     }
     return w;
@@ -3665,25 +3665,25 @@ int print_n_strings(conv_context_t *cntx, size_t n, const char *str)
             return snprint_n_strings(cntx, n, str);
 #ifdef FT_HAVE_WCHAR
         case W_CHAR_BUF:
-            cod_w = wsnprint_n_string(cntx->wbuf, cntx->raw_avail, n, str);
+            cod_w = wsnprint_n_string(cntx->u.wbuf, cntx->raw_avail, n, str);
             if (cod_w < 0)
                 return cod_w;
             raw_written = sizeof(wchar_t) * cod_w;
 
-            cntx->buf += raw_written;
+            cntx->u.buf += raw_written;
             cntx->raw_avail -= raw_written;
             return cod_w;
 #endif /* FT_HAVE_WCHAR */
 #ifdef FT_HAVE_UTF8
         case UTF8_BUF:
             /* Everying is very strange and differs with W_CHAR_BUF */
-            raw_written = u8nprint_n_strings(cntx->buf, cntx->raw_avail, n, str);
+            raw_written = u8nprint_n_strings(cntx->u.buf, cntx->raw_avail, n, str);
             if (raw_written < 0) {
                 fprintf(stderr, " raw_written = %d\n", raw_written);
                 return raw_written;
             }
 
-            cntx->buf += raw_written;
+            cntx->u.buf += raw_written;
             cntx->raw_avail -= raw_written;
             return utf8len(str) * n;
 #endif /* FT_HAVE_UTF8 */
@@ -3699,10 +3699,10 @@ int ft_nprint(conv_context_t *cntx, const char *str, size_t strlen)
     if (cntx->raw_avail + 1/* for 0 */ < strlen)
         return -1;
 
-    memcpy(cntx->buf, str, strlen);
-    cntx->buf += strlen;
+    memcpy(cntx->u.buf, str, strlen);
+    cntx->u.buf += strlen;
     cntx->raw_avail -= strlen;
-    *cntx->buf = '\0'; /* Do we need this ? */
+    *cntx->u.buf = '\0'; /* Do we need this ? */
     return strlen;
 }
 
@@ -3714,13 +3714,13 @@ int ft_nwprint(conv_context_t *cntx, const wchar_t *str, size_t strlen)
 
     size_t raw_len = strlen * sizeof(wchar_t);
 
-    memcpy(cntx->buf, str, raw_len);
-    cntx->buf += raw_len;
+    memcpy(cntx->u.buf, str, raw_len);
+    cntx->u.buf += raw_len;
     cntx->raw_avail -= raw_len;
 
     /* Do we need this ? */
     wchar_t end_of_string = L'\0';
-    memcpy(cntx->buf, &end_of_string, sizeof(wchar_t));
+    memcpy(cntx->u.buf, &end_of_string, sizeof(wchar_t));
     return strlen;
 }
 #endif /* FT_HAVE_WCHAR */
@@ -3735,10 +3735,10 @@ int ft_nu8print(conv_context_t *cntx, const void *beg, const void *end)
     if (cntx->raw_avail + 1 < raw_len)
         return -1;
 
-    memcpy(cntx->buf, beg, raw_len);
-    cntx->buf += raw_len;
+    memcpy(cntx->u.buf, beg, raw_len);
+    cntx->u.buf += raw_len;
     cntx->raw_avail -= raw_len;
-    *(char *)cntx->buf = '\0'; /* Do we need this ? */
+    *(cntx->u.buf) = '\0'; /* Do we need this ? */
     return raw_len; /* what return here ? */
 }
 #endif /* FT_HAVE_UTF8 */
diff --git a/src/fort_impl.c b/src/fort_impl.c
index 1aa2ab3..cfaa6cb 100644
--- a/src/fort_impl.c
+++ b/src/fort_impl.c
@@ -655,7 +655,7 @@ const void *ft_to_string_impl(const ft_table_t *table, enum str_buf_type b_type)
 
     conv_context_t cntx;
     cntx.buf_origin = buffer;
-    cntx.buf = buffer;
+    cntx.u.buf = buffer;
     cntx.raw_avail = string_buffer_raw_capacity(table->conv_buffer);
     cntx.cntx = &context;
     cntx.b_type = b_type;
diff --git a/src/fort_utils.c b/src/fort_utils.c
index e0e6a4f..c5bf74b 100644
--- a/src/fort_utils.c
+++ b/src/fort_utils.c
@@ -225,9 +225,9 @@ int snprint_n_strings_impl(char *buf, size_t length, size_t n, const char *str)
 static
 int snprint_n_strings(conv_context_t *cntx, size_t n, const char *str)
 {
-    int w = snprint_n_strings_impl(cntx->buf, cntx->raw_avail, n, str);
+    int w = snprint_n_strings_impl(cntx->u.buf, cntx->raw_avail, n, str);
     if (w >= 0) {
-        cntx->buf += w;
+        cntx->u.buf += w;
         cntx->raw_avail -= w;
     }
     return w;
@@ -255,25 +255,25 @@ int print_n_strings(conv_context_t *cntx, size_t n, const char *str)
             return snprint_n_strings(cntx, n, str);
 #ifdef FT_HAVE_WCHAR
         case W_CHAR_BUF:
-            cod_w = wsnprint_n_string(cntx->wbuf, cntx->raw_avail, n, str);
+            cod_w = wsnprint_n_string(cntx->u.wbuf, cntx->raw_avail, n, str);
             if (cod_w < 0)
                 return cod_w;
             raw_written = sizeof(wchar_t) * cod_w;
 
-            cntx->buf += raw_written;
+            cntx->u.buf += raw_written;
             cntx->raw_avail -= raw_written;
             return cod_w;
 #endif /* FT_HAVE_WCHAR */
 #ifdef FT_HAVE_UTF8
         case UTF8_BUF:
             /* Everying is very strange and differs with W_CHAR_BUF */
-            raw_written = u8nprint_n_strings(cntx->buf, cntx->raw_avail, n, str);
+            raw_written = u8nprint_n_strings(cntx->u.buf, cntx->raw_avail, n, str);
             if (raw_written < 0) {
                 fprintf(stderr, " raw_written = %d\n", raw_written);
                 return raw_written;
             }
 
-            cntx->buf += raw_written;
+            cntx->u.buf += raw_written;
             cntx->raw_avail -= raw_written;
             return utf8len(str) * n;
 #endif /* FT_HAVE_UTF8 */
@@ -289,10 +289,10 @@ int ft_nprint(conv_context_t *cntx, const char *str, size_t strlen)
     if (cntx->raw_avail + 1/* for 0 */ < strlen)
         return -1;
 
-    memcpy(cntx->buf, str, strlen);
-    cntx->buf += strlen;
+    memcpy(cntx->u.buf, str, strlen);
+    cntx->u.buf += strlen;
     cntx->raw_avail -= strlen;
-    *cntx->buf = '\0'; /* Do we need this ? */
+    *cntx->u.buf = '\0'; /* Do we need this ? */
     return strlen;
 }
 
@@ -304,13 +304,13 @@ int ft_nwprint(conv_context_t *cntx, const wchar_t *str, size_t strlen)
 
     size_t raw_len = strlen * sizeof(wchar_t);
 
-    memcpy(cntx->buf, str, raw_len);
-    cntx->buf += raw_len;
+    memcpy(cntx->u.buf, str, raw_len);
+    cntx->u.buf += raw_len;
     cntx->raw_avail -= raw_len;
 
     /* Do we need this ? */
     wchar_t end_of_string = L'\0';
-    memcpy(cntx->buf, &end_of_string, sizeof(wchar_t));
+    memcpy(cntx->u.buf, &end_of_string, sizeof(wchar_t));
     return strlen;
 }
 #endif /* FT_HAVE_WCHAR */
@@ -325,10 +325,10 @@ int ft_nu8print(conv_context_t *cntx, const void *beg, const void *end)
     if (cntx->raw_avail + 1 < raw_len)
         return -1;
 
-    memcpy(cntx->buf, beg, raw_len);
-    cntx->buf += raw_len;
+    memcpy(cntx->u.buf, beg, raw_len);
+    cntx->u.buf += raw_len;
     cntx->raw_avail -= raw_len;
-    *(char *)cntx->buf = '\0'; /* Do we need this ? */
+    *(cntx->u.buf) = '\0'; /* Do we need this ? */
     return raw_len; /* what return here ? */
 }
 #endif /* FT_HAVE_UTF8 */
diff --git a/src/fort_utils.h b/src/fort_utils.h
index 554c70e..c341001 100644
--- a/src/fort_utils.h
+++ b/src/fort_utils.h
@@ -139,7 +139,7 @@ struct conv_context {
     union {
         char *buf;
         wchar_t *wbuf;
-    };
+    } u;
     size_t raw_avail;
     struct fort_context *cntx;
     enum str_buf_type b_type;
diff --git a/tests/wb_tests/test_string_buffer.c b/tests/wb_tests/test_string_buffer.c
index e752aa6..fd2f020 100644
--- a/tests/wb_tests/test_string_buffer.c
+++ b/tests/wb_tests/test_string_buffer.c
@@ -607,24 +607,24 @@ static void test_print_n_strings_(const char *str, size_t n)
     {
         string_buffer_t *buffer = create_string_buffer(200, CHAR_BUF);
         conv_context_t cntx;
-        cntx.buf = (char *)buffer_get_data(buffer);
+        cntx.u.buf = (char *)buffer_get_data(buffer);
         cntx.buf_origin = (char *)buffer_get_data(buffer);
         cntx.raw_avail = 200;
         cntx.b_type = CHAR_BUF;
         assert_true(print_n_strings(&cntx, n, str) == sz);
-        assert_true(cntx.buf - cntx.buf_origin == (ptrdiff_t)sz);
+        assert_true(cntx.u.buf - cntx.buf_origin == (ptrdiff_t)sz);
         destroy_string_buffer(buffer);
     }
 
     {
         string_buffer_t *buffer = create_string_buffer(200, W_CHAR_BUF);
         conv_context_t cntx;
-        cntx.buf = (char *)buffer_get_data(buffer);
+        cntx.u.buf = (char *)buffer_get_data(buffer);
         cntx.buf_origin = (char *)buffer_get_data(buffer);
         cntx.raw_avail = 200;
         cntx.b_type = W_CHAR_BUF;
         assert_true(print_n_strings(&cntx, n, str) == /*sizeof(wchar_t) **/ sz);
-        assert_true(cntx.buf - cntx.buf_origin == (ptrdiff_t)sizeof(wchar_t) * sz);
+        assert_true(cntx.u.buf - cntx.buf_origin == (ptrdiff_t)sizeof(wchar_t) * sz);
         destroy_string_buffer(buffer);
     }
 
@@ -632,12 +632,12 @@ static void test_print_n_strings_(const char *str, size_t n)
     {
         string_buffer_t *buffer = create_string_buffer(200, UTF8_BUF);
         conv_context_t cntx;
-        cntx.buf = (char *)buffer_get_data(buffer);
+        cntx.u.buf = (char *)buffer_get_data(buffer);
         cntx.buf_origin = (char *)buffer_get_data(buffer);
         cntx.raw_avail = 200;
         cntx.b_type = UTF8_BUF;
         assert_true(print_n_strings(&cntx, n, str) ==  sz);
-        assert_true(cntx.buf - cntx.buf_origin == (ptrdiff_t)sz);
+        assert_true(cntx.u.buf - cntx.buf_origin == (ptrdiff_t)sz);
         destroy_string_buffer(buffer);
     }
 }