diff --git a/CMakeLists.txt b/CMakeLists.txt
index fab75bbd..c88771fc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -61,8 +61,8 @@ set(PROJECT_VERSION "${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}.${PROJECT
 include(GNUInstallDirs)
 
 ###############################################################################
-# Adhere strictly to old ANSI C89 / ISO C90 standard
-set(CMAKE_C_STANDARD 90)
+# Follow ISO C99 standard
+set(CMAKE_C_STANDARD 99)
 set(CMAKE_C_STANDARD_REQUIRED ON)
 set(CMAKE_C_EXTENSIONS ON)          # Use GNU extensions and POSIX standard
 
diff --git a/NEWS b/NEWS
index 84957df2..10a11d70 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,7 @@
+In Development:
+# Mentioning Check 0.13.0 for now, to fix distcheck target until next release
+
+
 Sat Oct 20, 2019: Released Check 0.13.0
   based on hash 2b18886a9a9d3bab44917a550d12128ad7e2c197
 
@@ -7,7 +11,7 @@ Sat Oct 20, 2019: Released Check 0.13.0
 * missing <unistd.h> in some files
   Issue #196 and Issue #186 (GitHub)
 
-* Varous documentation improvements
+* Various documentation improvements
 
 * END_TEST is now optional, as how START_TEST works has been redone
   Issue #158
diff --git a/index.html b/index.html
index ec00aec7..a0652887 100644
--- a/index.html
+++ b/index.html
@@ -56,7 +56,7 @@ <h3>Latest Check Release</h3>
 
 <p>
 <!-- Update this section during a release -->
-<b>Oct 20, 2017:</b> Check 0.12.0 <a href="https://github.com/libcheck/check/releases">
+<b>Oct 20, 2019:</b> Check 0.13.0 <a href="https://github.com/libcheck/check/releases">
 is now available for download</a>. Check is available under the
 <a href="./COPYING.LESSER">LGPL license</a>. New features available in
 this release are listed on the <a href="./NEWS">NEWS</a> page.
diff --git a/src/check_pack.c b/src/check_pack.c
index d815d784..f3858ff3 100644
--- a/src/check_pack.c
+++ b/src/check_pack.c
@@ -62,7 +62,7 @@ static size_t get_max_msg_size(void)
     size_t value = 0;
     char *env = getenv("CK_MAX_MSG_SIZE");
     if (env)
-        value = (size_t)strtoul(env, NULL, 10); // Cast in case size_t != unsigned long.
+        value = (size_t)strtoul(env, NULL, 10); /* Cast in case size_t != unsigned long. */
     if (value == 0)
         value = ck_max_msg_size;
     if (value == 0)
diff --git a/src/check_run.c b/src/check_run.c
index 7e212e02..2d0a7089 100644
--- a/src/check_run.c
+++ b/src/check_run.c
@@ -29,6 +29,10 @@
 #include <signal.h>
 #include <setjmp.h>
 
+#if defined(HAVE_FORK) && HAVE_FORK==1
+# include <sys/wait.h>
+#endif
+
 #include "check.h"
 #include "check_error.h"
 #include "check_list.h"
diff --git a/tests/check_check_master.c b/tests/check_check_master.c
index e7c38c71..6e40c783 100644
--- a/tests/check_check_master.c
+++ b/tests/check_check_master.c
@@ -43,10 +43,10 @@ char * line_num_failures_file_name = NULL;
 
 enum ck_test_msg_type_t {
 #if ENABLE_REGEX
-  // For tests with different output on different platforms
+  /* For tests with different output on different platforms */
   CK_MSG_REGEXP,
 #endif
-  // Simple text
+  /* Simple text */
   CK_MSG_TEXT
 };
 
diff --git a/tests/check_check_sub.c b/tests/check_check_sub.c
index a6f8f272..ddfea1d2 100644
--- a/tests/check_check_sub.c
+++ b/tests/check_check_sub.c
@@ -936,7 +936,7 @@ START_TEST(test_ck_assert_float_finite)
   record_test_name(tcase_name());
 
   ck_assert_float_finite(x);
-  // MS VS doesn't allow explicit division by zero
+  /* MS VS doesn't allow explicit division by zero */
   x = 1.0f / (1.0f - t);
   record_failure_line_num(__LINE__);
   ck_assert_float_finite(x);
@@ -1452,7 +1452,7 @@ START_TEST(test_ck_assert_double_finite)
   record_test_name(tcase_name());
 
   ck_assert_double_finite(x);
-  // MS VS doesn't allow explicit division by zero
+  /* MS VS doesn't allow explicit division by zero */
   x = 1.0 / (1.0 - t);
   record_failure_line_num(__LINE__);
   ck_assert_double_finite(x);
@@ -1970,7 +1970,7 @@ START_TEST(test_ck_assert_ldouble_finite)
   record_test_name(tcase_name());
 
   ck_assert_ldouble_finite(x);
-  // MS VS doesn't allow explicit division by zero
+  /* MS VS doesn't allow explicit division by zero */
   x = 1.0l / (1.0l - t);
   record_failure_line_num(__LINE__);
   ck_assert_ldouble_finite(x);
diff --git a/tests/check_set_max_msg_size.c b/tests/check_set_max_msg_size.c
index 6ebfc8e4..92a3bab5 100644
--- a/tests/check_set_max_msg_size.c
+++ b/tests/check_set_max_msg_size.c
@@ -64,8 +64,8 @@ int main (int argc, char *argv[])
      * Run the test suite. This is intended to trigger the "Message is too long" error.
      * Actual success/failure is determined by examining the output.
      */
-    check_set_max_msg_size(32);            // 1st call has no effect since
-    check_set_max_msg_size(atoi(argv[1])); // the 2nd call will override it.
+    check_set_max_msg_size(32);            /* 1st call has no effect since   */
+    check_set_max_msg_size(atoi(argv[1])); /* the 2nd call will override it. */
     sr = srunner_create(make_set_max_msg_size_suite());
     srunner_run_all(sr, CK_NORMAL);
     srunner_free(sr);