diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4b60c9d2..c2e69e3a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -69,7 +69,7 @@ add_library(otherbackends STATIC
 add_subdirectory(otherbackends)
 
 add_executable(testcrypt
-  testcrypt.c sshpubk.c ssh/crc-attack-detector.c)
+  test/testcrypt.c sshpubk.c ssh/crc-attack-detector.c)
 target_link_libraries(testcrypt
   keygen crypto utils ${platform_libraries})
 
diff --git a/testcrypt-enum.h b/test/testcrypt-enum.h
similarity index 100%
rename from testcrypt-enum.h
rename to test/testcrypt-enum.h
diff --git a/testcrypt.h b/test/testcrypt-func.h
similarity index 100%
rename from testcrypt.h
rename to test/testcrypt-func.h
diff --git a/testcrypt.c b/test/testcrypt.c
similarity index 97%
rename from testcrypt.c
rename to test/testcrypt.c
index 68e2d11d..e8593431 100644
--- a/testcrypt.c
+++ b/test/testcrypt.c
@@ -1133,11 +1133,11 @@ OPTIONAL_PTR_FUNC(string)
 
 /*
  * HERE BE DRAGONS: the horrible C preprocessor business that reads
- * testcrypt.h and generates a marshalling wrapper for each exported
- * function.
+ * testcrypt-func.h and generates a marshalling wrapper for each
+ * exported function.
  *
  * In an ideal world, we would start from a specification like this in
- * testcrypt.h
+ * testcrypt-func.h
  *
  *    FUNC(val_foo, example, (ARG(val_bar, bar), ARG(uint, n)))
  *
@@ -1159,14 +1159,14 @@ OPTIONAL_PTR_FUNC(string)
  *
  * With a more general macro processor such as m4, or custom code in
  * Perl or Python, or a helper program like llvm-tblgen, we could just
- * do that directly, reading function specifications from testcrypt.h
- * and writing out exactly the above. But we don't have a fully
- * general macro processor (since everything in that category
- * introduces an extra build dependency that's awkward on plain
- * Windows, or requires compiling and running a helper program which
- * is awkward in a cross-compile). We only have cpp. And in cpp, a
- * macro can't expand one of its arguments differently in two parts of
- * its own expansion. So we have to be more clever.
+ * do that directly, reading function specifications from
+ * testcrypt-func.h and writing out exactly the above. But we don't
+ * have a fully general macro processor (since everything in that
+ * category introduces an extra build dependency that's awkward on
+ * plain Windows, or requires compiling and running a helper program
+ * which is awkward in a cross-compile). We only have cpp. And in cpp,
+ * a macro can't expand one of its arguments differently in two parts
+ * of its own expansion. So we have to be more clever.
  *
  * In place of the above code, I instead generate three successive
  * declarations for each function. In simplified form they would look
@@ -1191,8 +1191,8 @@ OPTIONAL_PTR_FUNC(string)
  *
  * Each of these mentions the arguments and their types just _once_,
  * so each one can be generated by a single expansion of the FUNC(...)
- * specification in testcrypt.h, with FUNC and ARG and VOID defined to
- * appropriate values.
+ * specification in testcrypt-func.h, with FUNC and ARG and VOID
+ * defined to appropriate values.
  *
  * Or ... *nearly*. In fact, I left out several details there, but
  * it's a good starting point to understand the full version.
@@ -1251,8 +1251,8 @@ OPTIONAL_PTR_FUNC(string)
  * containing *two* int variables, and in between them is the vital
  * comma that we need!
  *
- * So in that pass through testcrypt.h, the ARG(type, name) macro has
- * to expand to the weird piece of text
+ * So in that pass through testcrypt-func.h, the ARG(type, name) macro
+ * has to expand to the weird piece of text
  *
  *             _predummy_name;   // terminating the previous int declaration
  *        TD_type name;          // declaring the thing we actually wanted
@@ -1309,8 +1309,8 @@ OPTIONAL_PTR_FUNC(string)
  * Finally, what if a wrapped function has _no_ arguments? Two out of
  * three uses of the argument list here need some kind of special case
  * for that. That's why you have to write 'VOID' explicitly in an
- * empty argument list in testcrypt.h: we make VOID expand to whatever
- * is needed to avoid a syntax error in that special case.
+ * empty argument list in testcrypt-func.h: we make VOID expand to
+ * whatever is needed to avoid a syntax error in that special case.
  */
 
 #define DEPARENTHESISE(...) __VA_ARGS__
@@ -1326,7 +1326,7 @@ OPTIONAL_PTR_FUNC(string)
     typedef struct ARGS_##fname {                       \
         int DEPARENTHESISE args;                        \
     } ARGS_##fname;
-#include "testcrypt.h"
+#include "testcrypt-func.h"
 #undef FUNC_INNER
 #undef ARG
 #undef VOID
@@ -1340,7 +1340,7 @@ OPTIONAL_PTR_FUNC(string)
         args;                                                           \
         return _args;                                                   \
     }
-#include "testcrypt.h"
+#include "testcrypt-func.h"
 #undef FUNC_INNER
 #undef ARG
 #undef VOID
@@ -1353,7 +1353,7 @@ OPTIONAL_PTR_FUNC(string)
         (void)_args; /* suppress warning if no actual arguments */      \
         return_##outtype(_out, realname args);                          \
     }
-#include "testcrypt.h"
+#include "testcrypt-func.h"
 #undef FUNC_INNER
 #undef ARG
 
@@ -1383,7 +1383,7 @@ static void process_line(BinarySource *in, strbuf *out)
 #define ARG1(type, arg)
 #define ARGN(type, arg)
 #define VOID
-#include "testcrypt.h"
+#include "testcrypt-func.h"
 #undef FUNC_INNER
 #undef ARG
 #undef VOID
diff --git a/test/testcrypt.py b/test/testcrypt.py
index b71f851d..18a741d5 100644
--- a/test/testcrypt.py
+++ b/test/testcrypt.py
@@ -313,7 +313,7 @@ def _lex_testcrypt_header(header):
     while pos < end:
         m = pat.match(header, pos)
         assert m is not None, (
-            "Failed to lex testcrypt.h at byte position {:d}".format(pos))
+            "Failed to lex testcrypt-func.h at byte position {:d}".format(pos))
 
         pos = m.end()
         tok = m.group(1)
@@ -339,7 +339,7 @@ def _parse_testcrypt_header(tokens):
             description = lambda: "'"+what+"' "
             ok = tok == what
         if not ok:
-            sys.exit("testcrypt.h:{:d}: expected {}{}".format(
+            sys.exit("testcrypt-func.h:{:d}: expected {}{}".format(
                 pos, description(), why))
         return tok
 
@@ -392,7 +392,7 @@ def _setup(scope):
             arg = arg[:arg.index("_", len(valprefix))]
         return arg
 
-    with open(os.path.join(putty_srcdir, "testcrypt.h")) as f:
+    with open(os.path.join(putty_srcdir, "test", "testcrypt-func.h")) as f:
         header = f.read()
     tokens = _lex_testcrypt_header(header)
     for function, rettype, arglist in _parse_testcrypt_header(tokens):
diff --git a/testsc.c b/test/testsc.c
similarity index 100%
rename from testsc.c
rename to test/testsc.c
diff --git a/testzlib.c b/test/testzlib.c
similarity index 100%
rename from testzlib.c
rename to test/testzlib.c
diff --git a/unix/CMakeLists.txt b/unix/CMakeLists.txt
index 825ac35f..cff15de0 100644
--- a/unix/CMakeLists.txt
+++ b/unix/CMakeLists.txt
@@ -98,11 +98,11 @@ add_executable(cgtest
 target_link_libraries(cgtest keygen console crypto utils)
 
 add_executable(testsc
-  ${CMAKE_SOURCE_DIR}/testsc.c)
+  ${CMAKE_SOURCE_DIR}/test/testsc.c)
 target_link_libraries(testsc keygen crypto utils)
 
 add_executable(testzlib
-  ${CMAKE_SOURCE_DIR}/testzlib.c
+  ${CMAKE_SOURCE_DIR}/test/testzlib.c
   ${CMAKE_SOURCE_DIR}/ssh/zlib.c)
 target_link_libraries(testzlib utils)