diff --git a/Makefile.am b/Makefile.am
index 20b5d335..71fa398d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -63,7 +63,7 @@ lib_LTLIBRARIES += src/libespeak-ng.la
 
 src_libespeak_ng_la_LDFLAGS = -version-info $(SHARED_VERSION) -lpthread
 src_libespeak_ng_la_CFLAGS = -Isrc/include/espeak-ng \
-	-fPIC -fvisibility=hidden -D LIBRARY \
+	-fPIC -fvisibility=hidden -D LIBRARY -D _BSD_SOURCE -D _POSIX_C_SOURCE=200112L \
 	-pedantic -fno-exceptions -D PATH_ESPEAK_DATA=\"$(DATADIR)\"
 src_libespeak_ng_la_SOURCES = \
 	src/libespeak-ng/compiledata.c \
@@ -141,7 +141,7 @@ bin_PROGRAMS += src/speak-ng
 
 src_speak_ng_LDADD   = src/libespeak-ng.la
 src_speak_ng_LDFLAGS = -static
-src_speak_ng_CFLAGS  = -Isrc/libespeak-ng -Isrc/include/espeak-ng
+src_speak_ng_CFLAGS  = -Isrc/libespeak-ng -Isrc/include/espeak-ng -D _POSIX_C_SOURCE=200112L
 src_speak_ng_SOURCES = src/speak-ng.c
 
 bin_PROGRAMS += src/espeak-ng
diff --git a/src/libespeak-ng/compiledata.c b/src/libespeak-ng/compiledata.c
index 47b4bbfc..720caae4 100644
--- a/src/libespeak-ng/compiledata.c
+++ b/src/libespeak-ng/compiledata.c
@@ -20,6 +20,7 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <strings.h>
 #include <ctype.h>
 #include <stdlib.h>
 #include <time.h>
diff --git a/src/libespeak-ng/compilembrola.c b/src/libespeak-ng/compilembrola.c
index 8c5b3199..9830f9bd 100644
--- a/src/libespeak-ng/compilembrola.c
+++ b/src/libespeak-ng/compilembrola.c
@@ -19,6 +19,8 @@
  ***************************************************************************/
 
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
 #include "speak_lib.h"
 #include "espeak_ng.h"