diff --git a/CMakeLists.txt b/CMakeLists.txt
index da4461d..5f50f77 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -21,7 +21,8 @@ set(SOURCES
   src/widgets/flog.c
   src/widgets/gscreen.c
   # ctype
-  src/ctype/trivialties.c
+  src/ctype/charprops.c
+  src/ctype/classes.c
   # string
   src/string/memarray.c
   src/string/core.c
diff --git a/include/ft/all-tests.h b/include/ft/all-tests.h
index bf261b7..7fef70f 100644
--- a/include/ft/all-tests.h
+++ b/include/ft/all-tests.h
@@ -8,9 +8,8 @@
 #include <ft/test.h>
 
 /* ctype */
-extern ft_test ft_ctype_trivial_success;
-extern ft_test ft_ctype_trivial_failure;
-extern ft_test ft_ctype_trivial_empty;
+extern ft_test ft_ctype_macros;
+extern ft_test ft_ctype_functions;
 
 /* string */
 extern ft_test ft_string_memset;
diff --git a/src/ctype/charprops.c b/src/ctype/charprops.c
new file mode 100644
index 0000000..bf78706
--- /dev/null
+++ b/src/ctype/charprops.c
@@ -0,0 +1,134 @@
+#include <ft/test.h>
+#include <ft/all-tests.h>
+#include "charprops.h"
+
+uint16_t charprops[128] = {
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL | CP_SPACE | CP_BLANK,
+    CP_CNTRL | CP_SPACE,
+    CP_CNTRL | CP_SPACE,
+    CP_CNTRL | CP_SPACE,
+    CP_CNTRL | CP_SPACE,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_CNTRL,
+    CP_PRINT | CP_SPACE | CP_BLANK,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_DIGIT | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_DIGIT | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_DIGIT | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_DIGIT | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_DIGIT | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_DIGIT | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_DIGIT | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_DIGIT | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_DIGIT | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_DIGIT | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_UPPER,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER | CP_XDIGIT,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_ALNUM | CP_ALPHA | CP_LOWER,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_PRINT | CP_GRAPH | CP_PUNCT,
+    CP_CNTRL,
+};
diff --git a/src/ctype/charprops.h b/src/ctype/charprops.h
new file mode 100644
index 0000000..7b6986a
--- /dev/null
+++ b/src/ctype/charprops.h
@@ -0,0 +1,29 @@
+//---
+// ctype.charprops: Utilities to validate properties of groups of characters
+//
+// These utilities simply factor in the common code in ctype macro vs function
+// tests, and in a way implement the ctype specification in a naive way in
+// order to compare results.
+//---
+
+#ifndef _CTYPE_CHARPROPS_H
+#define _CTYPE_CHARPROPS_H
+
+#include <gint/defs/types.h>
+
+#define CP_CNTRL   0x0001
+#define CP_PRINT   0x0002
+#define CP_SPACE   0x0004
+#define CP_BLANK   0x0008
+#define CP_GRAPH   0x0010
+#define CP_PUNCT   0x0020
+#define CP_ALNUM   0x0040
+#define CP_ALPHA   0x0080
+#define CP_UPPER   0x0100
+#define CP_LOWER   0x0200
+#define CP_DIGIT   0x0400
+#define CP_XDIGIT  0x0800
+
+extern uint16_t charprops[128];
+
+#endif /* _CTYPE_CHARPROPS_H */
diff --git a/src/ctype/classes.c b/src/ctype/classes.c
new file mode 100644
index 0000000..7ee4176
--- /dev/null
+++ b/src/ctype/classes.c
@@ -0,0 +1,66 @@
+#include <ft/test.h>
+#include <ft/all-tests.h>
+#include <ctype.h>
+
+#include "charprops.h"
+
+static void _ctype_macros(ft_test *t)
+{
+    for(int c = 0; c < 128; c++) {
+        ft_assert(t, (isalnum(c)  != 0) == ((charprops[c] & CP_ALNUM)  != 0));
+        ft_assert(t, (isalpha(c)  != 0) == ((charprops[c] & CP_ALPHA)  != 0));
+        ft_assert(t, (isblank(c)  != 0) == ((charprops[c] & CP_BLANK)  != 0));
+        ft_assert(t, (iscntrl(c)  != 0) == ((charprops[c] & CP_CNTRL)  != 0));
+        ft_assert(t, (isdigit(c)  != 0) == ((charprops[c] & CP_DIGIT)  != 0));
+        ft_assert(t, (islower(c)  != 0) == ((charprops[c] & CP_LOWER)  != 0));
+        ft_assert(t, (isgraph(c)  != 0) == ((charprops[c] & CP_GRAPH)  != 0));
+        ft_assert(t, (ispunct(c)  != 0) == ((charprops[c] & CP_PUNCT)  != 0));
+        ft_assert(t, (isprint(c)  != 0) == ((charprops[c] & CP_PRINT)  != 0));
+        ft_assert(t, (isspace(c)  != 0) == ((charprops[c] & CP_SPACE)  != 0));
+        ft_assert(t, (isupper(c)  != 0) == ((charprops[c] & CP_UPPER)  != 0));
+        ft_assert(t, (isxdigit(c) != 0) == ((charprops[c] & CP_XDIGIT) != 0));
+    }
+}
+
+ft_test ft_ctype_macros = {
+    .name = "Macro versions of functions",
+    .function = _ctype_macros,
+};
+
+#undef isalnum
+#undef isalpha
+#undef isblank
+#undef iscntrl
+#undef isdigit
+#undef islower
+#undef isgraph
+#undef ispunct
+#undef isprint
+#undef isspace
+#undef isupper
+#undef isxdigit
+#undef tolower
+#undef toupper
+
+static void _ctype_functions(ft_test *t)
+{
+    for(int c = 0; c < 128; c++) {
+        ft_assert(t, (isalnum(c)  != 0) == ((charprops[c] & CP_ALNUM)  != 0));
+        ft_assert(t, (isalpha(c)  != 0) == ((charprops[c] & CP_ALPHA)  != 0));
+        ft_assert(t, (isblank(c)  != 0) == ((charprops[c] & CP_BLANK)  != 0));
+        ft_assert(t, (iscntrl(c)  != 0) == ((charprops[c] & CP_CNTRL)  != 0));
+        ft_assert(t, (isdigit(c)  != 0) == ((charprops[c] & CP_DIGIT)  != 0));
+        ft_assert(t, (islower(c)  != 0) == ((charprops[c] & CP_LOWER)  != 0));
+        ft_assert(t, (isgraph(c)  != 0) == ((charprops[c] & CP_GRAPH)  != 0));
+        ft_assert(t, (ispunct(c)  != 0) == ((charprops[c] & CP_PUNCT)  != 0));
+        ft_assert(t, (isprint(c)  != 0) == ((charprops[c] & CP_PRINT)  != 0));
+        ft_assert(t, (isspace(c)  != 0) == ((charprops[c] & CP_SPACE)  != 0));
+        ft_assert(t, (isupper(c)  != 0) == ((charprops[c] & CP_UPPER)  != 0));
+        ft_assert(t, (isxdigit(c) != 0) == ((charprops[c] & CP_XDIGIT) != 0));
+    }
+}
+
+ft_test ft_ctype_functions = {
+    .name = "Pure functions",
+    .function = _ctype_functions,
+};
diff --git a/src/ctype/trivialties.c b/src/ctype/trivialties.c
deleted file mode 100644
index 9e3313f..0000000
--- a/src/ctype/trivialties.c
+++ /dev/null
@@ -1,28 +0,0 @@
-#include <ft/test.h>
-#include <ft/all-tests.h>
-
-static void _ctype_trivial_success(ft_test *t)
-{
-    ft_assert(t, 1);
-    ft_assert(t, 1);
-}
-
-ft_test ft_ctype_trivial_success = {
-    .name = "Trivialty (always succeeds)",
-    .function = _ctype_trivial_success,
-};
-
-static void _ctype_trivial_failure(ft_test *t)
-{
-    ft_assert(t, 0);
-}
-
-ft_test ft_ctype_trivial_failure = {
-    .name = "Trivialty (always fails)",
-    .function = _ctype_trivial_failure,
-};
-
-ft_test ft_ctype_trivial_empty = {
-    .name = "Trivialty (no function)",
-    .function = NULL,
-};
diff --git a/src/main.c b/src/main.c
index ec08a71..ccd63fb 100644
--- a/src/main.c
+++ b/src/main.c
@@ -14,9 +14,8 @@
 
 ft_list headers_libc[] = {
     { "<ctype.h>", (ft_test*[]){
-        &ft_ctype_trivial_success,
-        &ft_ctype_trivial_failure,
-        &ft_ctype_trivial_empty,
+        &ft_ctype_macros,
+        &ft_ctype_functions,
         NULL,
     }},
     { "<locale.h>", NULL },