diff --git a/.cmake/Modules/Capabilities.cmake b/.cmake/Modules/Capabilities.cmake
index ad93937..006cf22 100644
--- a/.cmake/Modules/Capabilities.cmake
+++ b/.cmake/Modules/Capabilities.cmake
@@ -4,6 +4,7 @@
 
 include(CheckPrototypeDefinition)
 include(CheckLibraryExists)
+include(CheckFunctionExists)
 include(PackageUtils)
 
 # Check for packages
@@ -21,12 +22,8 @@ cr_find_package (PCRE PKGCONFIG libpcre)
 
 # Check for functions
 
-check_prototype_definition(
-  strtok_s
-  "char *strtok_s(char *strToken, const char *strDelimit, char **context)"
-  NULL
-  "string.h"
-  HAVE_STRTOK_S)
+check_function_exists(strtok_s HAVE_STRTOK_S)
+check_function_exists(strtok_r HAVE_STRTOK_R)
 
 check_library_exists (rt clock_gettime "time.h" HAVE_CLOCK_GETTIME)
 
diff --git a/src/compat/strtok.h b/src/compat/strtok.h
index 78fc227..f733bdd 100644
--- a/src/compat/strtok.h
+++ b/src/compat/strtok.h
@@ -27,12 +27,14 @@
 # include "config.h"
 
 # ifdef VANILLA_WIN32
-#  if HAVE_STRTOK_S
-#   define strtok_r strtok_s
-#  else
+#  if !HAVE_STRTOK_R
+#   if HAVE_STRTOK_S
+#    define strtok_r strtok_s
+#   else
 static CR_INLINE char *strtok_r(char *str, const char *delim, CR_UNUSED char **saveptr) {
   return strtok(str, delim);
 }
+#   endif
 #  endif
 
 #  ifdef _MSC_VER
diff --git a/src/config.h.in b/src/config.h.in
index 0040dad..4561f06 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -6,6 +6,7 @@
 #cmakedefine ENABLE_VALGRIND_ERRORS @ENABLE_VALGRIND_ERRORS@
 #cmakedefine MINGW_DEFINE_OFF_T @MINGW_DEFINE_OFF_T@
 #cmakedefine01 HAVE_STRTOK_S
+#cmakedefine01 HAVE_STRTOK_R
 
 # define LOCALEDIR "${LOCALEDIR}"
 # define PACKAGE "${PROJECT_NAME}"