diff --git a/ChangeLog b/ChangeLog
index 7fc9a65f..f67430e1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -11,6 +11,7 @@ v0.39.4		08-Dec-2003
 		Revised configure and all Makefiles for better support of
 		linking with threads libraries.
 		Changed endian tests using the configure script.
+		Changed compiler flags for threads.
 
 	upgrade:
 		If you didn't change anything of the language defaults then
diff --git a/configure b/configure
index 62b12acb..cf1977e4 100755
--- a/configure
+++ b/configure
@@ -2877,9 +2877,9 @@ else
    debugging=no
 fi;
 if test "$debugging" = "yes"; then
-    CFLAGS="-O -g -Wall -Wshadow -Wwrite-strings -Wstrict-prototypes"
+    CFLAGS="-O -g -Wall -Wshadow -Wwrite-strings -Wstrict-prototypes -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS"
 else
-    CFLAGS="-O3 -Wall -Wshadow -Wwrite-strings -Wstrict-prototypes"
+    CFLAGS="-O3 -Wall -Wshadow -Wwrite-strings -Wstrict-prototypes -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS"
 fi
 
 
diff --git a/configure.in b/configure.in
index 832e3cf7..7ae904f1 100644
--- a/configure.in
+++ b/configure.in
@@ -68,9 +68,9 @@ if test "$experiment" = "yes"; then
 fi
 AC_ARG_ENABLE(debugging,   [  --enable-debugging      Compile for debugging], [ debugging=$enableval ], [ debugging=no ])
 if test "$debugging" = "yes"; then
-    CFLAGS="-O -g -Wall -Wshadow -Wwrite-strings -Wstrict-prototypes"
+    CFLAGS="-O -g -Wall -Wshadow -Wwrite-strings -Wstrict-prototypes -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS"
 else
-    CFLAGS="-O3 -Wall -Wshadow -Wwrite-strings -Wstrict-prototypes"
+    CFLAGS="-O3 -Wall -Wshadow -Wwrite-strings -Wstrict-prototypes -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS"
 fi 
 
 
diff --git a/mbtask/Makefile b/mbtask/Makefile
index a9797eae..1b0a969b 100644
--- a/mbtask/Makefile
+++ b/mbtask/Makefile
@@ -19,7 +19,7 @@ OTHER		= Makefile issue issue.netbsd
 #############################################################################
 
 .c.o:
-		${CC} ${CFLAGS} -D_REENTRANT -D_POSIX_PTHREAD_SEMANTICS ${INCLUDES} ${DEFINES} -c $<
+		${CC} ${CFLAGS} ${INCLUDES} ${DEFINES} -c $<
 
 all:		mbtask