diff --git a/.travis.yml b/.travis.yml
index bc355a8..b2afcdb 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -104,7 +104,10 @@ script:
   # cppcheck run
   - |
     if [ "${FORT_C_COMPILER}" = "gcc-8" ]; then
-      cppcheck --enable=warning,style,performance,portability,information,missingInclude --error-exitcode=1 lib
+      cppcheck --std=posix --enable=warning,style,performance,portability,information,missingInclude --error-exitcode=1 lib
+      cppcheck --std=c89 --enable=warning,style,performance,portability,information,missingInclude --error-exitcode=1 lib
+      cppcheck --std=c99 --enable=warning,style,performance,portability,information,missingInclude --error-exitcode=1 lib
+      cppcheck --std=c++11 --enable=warning,style,performance,portability,information,missingInclude --error-exitcode=1 lib
     fi
 
   # Print all environment variables to aid in CI development
diff --git a/lib/fort.c b/lib/fort.c
index fa852b4..00efd0d 100644
--- a/lib/fort.c
+++ b/lib/fort.c
@@ -4945,8 +4945,8 @@ FT_INTERNAL
 size_t buffer_text_width(string_buffer_t *buffer)
 {
     size_t max_length = 0;
-    int n = 0;
     if (buffer->type == CharBuf) {
+        int n = 0;
         while (1) {
             const char *beg = NULL;
             const char *end = NULL;
@@ -4959,6 +4959,7 @@ size_t buffer_text_width(string_buffer_t *buffer)
         }
 #ifdef FT_HAVE_WCHAR
     } else {
+        int n = 0;
         while (1) {
             const wchar_t *beg = NULL;
             const wchar_t *end = NULL;
@@ -5307,6 +5308,7 @@ fort_status_t get_table_sizes(const ft_table_t *table, size_t *rows, size_t *col
         *rows = vector_size(table->rows);
         fort_row_t *row = NULL;
         FOR_EACH(fort_row_t *, row, table->rows) {
+            (void)i0;
             size_t cols_in_row = columns_in_row(row);
             if (cols_in_row > *cols)
                 *cols = cols_in_row;
diff --git a/src/string_buffer.c b/src/string_buffer.c
index dee01d3..1bb816a 100644
--- a/src/string_buffer.c
+++ b/src/string_buffer.c
@@ -307,8 +307,8 @@ FT_INTERNAL
 size_t buffer_text_width(string_buffer_t *buffer)
 {
     size_t max_length = 0;
-    int n = 0;
     if (buffer->type == CharBuf) {
+        int n = 0;
         while (1) {
             const char *beg = NULL;
             const char *end = NULL;
@@ -321,6 +321,7 @@ size_t buffer_text_width(string_buffer_t *buffer)
         }
 #ifdef FT_HAVE_WCHAR
     } else {
+        int n = 0;
         while (1) {
             const wchar_t *beg = NULL;
             const wchar_t *end = NULL;
diff --git a/src/table.c b/src/table.c
index 12a4bb3..1e3d606 100644
--- a/src/table.c
+++ b/src/table.c
@@ -110,6 +110,7 @@ fort_status_t get_table_sizes(const ft_table_t *table, size_t *rows, size_t *col
         *rows = vector_size(table->rows);
         fort_row_t *row = NULL;
         FOR_EACH(fort_row_t *, row, table->rows) {
+            (void)i0;
             size_t cols_in_row = columns_in_row(row);
             if (cols_in_row > *cols)
                 *cols = cols_in_row;