diff --git a/configure/os/CONFIG.Common.RTEMS b/configure/os/CONFIG.Common.RTEMS
index b05c6ef26..b2a058196 100644
--- a/configure/os/CONFIG.Common.RTEMS
+++ b/configure/os/CONFIG.Common.RTEMS
@@ -100,8 +100,9 @@ CODE_CXXFLAGS =
 
 #--------------------------------------------------
 # RTEMS uses the inline keyword so -pedantic causes too many problems.
-CONFORM_CFLAGS_STRICT = -ansi
-CONFORM_CXXFLAGS_STRICT = -ansi
+# Using -ansi turns off lots of useful prototypes (e.g. strtok_r).
+CONFORM_CFLAGS_STRICT =
+CONFORM_CXXFLAGS_STRICT =
 
 #--------------------------------------------------
 # Command-line input support