diff --git a/src/libopensc/card-emv.c b/src/libopensc/card-emv.c
index cf8f7ae8..df7fac5b 100644
--- a/src/libopensc/card-emv.c
+++ b/src/libopensc/card-emv.c
@@ -20,6 +20,7 @@
 
 #include "sc-internal.h"
 #include "sc-log.h"
+#include <string.h>
 
 static struct sc_card_operations emv_ops;
 static const struct sc_card_driver emv_drv = {
diff --git a/src/libopensc/card-flex.c b/src/libopensc/card-flex.c
index 9b193cfa..1c4652f2 100644
--- a/src/libopensc/card-flex.c
+++ b/src/libopensc/card-flex.c
@@ -21,6 +21,7 @@
 #include "sc-internal.h"
 #include "sc-log.h"
 #include <stdlib.h>
+#include <string.h>
 
 static const char *flex_atrs[] = {
 	"3B:95:94:40:FF:63:01:01:02:01", /* Cryptoflex 16k */
diff --git a/src/libopensc/card-tcos.c b/src/libopensc/card-tcos.c
index a7edb568..9b6ba9b6 100644
--- a/src/libopensc/card-tcos.c
+++ b/src/libopensc/card-tcos.c
@@ -20,6 +20,7 @@
 
 #include "sc-internal.h"
 #include "sc-log.h"
+#include <string.h>
 
 static const char *tcos_atrs[] = {
 	"3B:BA:96:00:81:31:86:5D:00:64:05:60:02:03:31:80:90:00:66",
diff --git a/src/libopensc/card.c b/src/libopensc/card.c
index 65f5e3aa..a5215219 100644
--- a/src/libopensc/card.c
+++ b/src/libopensc/card.c
@@ -23,6 +23,7 @@
 #include "sc-asn1.h"
 #include <assert.h>
 #include <stdlib.h>
+#include <string.h>
 
 int sc_check_sw(struct sc_card *card, int sw1, int sw2)
 {
diff --git a/src/libopensc/iso7816.c b/src/libopensc/iso7816.c
index c7a042c5..130d3eb2 100644
--- a/src/libopensc/iso7816.c
+++ b/src/libopensc/iso7816.c
@@ -24,6 +24,7 @@
 
 #include <assert.h>
 #include <ctype.h>
+#include <string.h>
 
 const static struct sc_card_error iso7816_errors[] = {
 	{ 0x6200, SC_ERROR_UNKNOWN_REPLY,	"State of non-volatile memory unchanged" },
diff --git a/src/openssh/opensc-ssh.c b/src/openssh/opensc-ssh.c
index 091d4187..8be8d34e 100644
--- a/src/openssh/opensc-ssh.c
+++ b/src/openssh/opensc-ssh.c
@@ -14,6 +14,7 @@
 
 #include <opensc.h>
 #include <opensc-pkcs15.h>
+#include <string.h>
 
 int quiet = 0;
 char *opt_outfile = NULL;
diff --git a/src/pkcs11/misc.c b/src/pkcs11/misc.c
index 0a1863d3..32571d00 100644
--- a/src/pkcs11/misc.c
+++ b/src/pkcs11/misc.c
@@ -22,6 +22,7 @@
 #include <malloc.h>
 #include "sc-pkcs11.h"
 #include <sc-log.h>
+#include <string.h>
 
 #define DUMP_TEMPLATE_MAX	32
 
diff --git a/src/pkcs11/pkcs11-global.c b/src/pkcs11/pkcs11-global.c
index 53ff6ea4..12259671 100644
--- a/src/pkcs11/pkcs11-global.c
+++ b/src/pkcs11/pkcs11-global.c
@@ -22,6 +22,7 @@
 #include "sc-pkcs11.h"
 
 #include <sc-log.h>
+#include <string.h>
 
 struct sc_context *context = NULL;
 struct sc_pkcs11_pool session_pool;
diff --git a/src/pkcs11/pkcs11-session.c b/src/pkcs11/pkcs11-session.c
index d5c3ae33..6a90f7bd 100644
--- a/src/pkcs11/pkcs11-session.c
+++ b/src/pkcs11/pkcs11-session.c
@@ -23,6 +23,7 @@
 #include <malloc.h>
 #include "sc-pkcs11.h"
 #include <sc-log.h>
+#include <string.h>
 
 CK_RV C_OpenSession(CK_SLOT_ID            slotID,        /* the slot's ID */
 		    CK_FLAGS              flags,         /* defined in CK_SESSION_INFO */
diff --git a/src/pkcs11/slot.c b/src/pkcs11/slot.c
index 6f691c8c..267633e7 100644
--- a/src/pkcs11/slot.c
+++ b/src/pkcs11/slot.c
@@ -20,6 +20,7 @@
 
 #include "sc-pkcs11.h"
 #include <sc-log.h>
+#include <string.h>
 
 static struct sc_pkcs11_framework_ops *frameworks[] = {
         &framework_pkcs15,
diff --git a/src/tests/pintest.c b/src/tests/pintest.c
index 87d2df3f..4cfe15cd 100644
--- a/src/tests/pintest.c
+++ b/src/tests/pintest.c
@@ -10,6 +10,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <string.h>
 
 struct sc_pkcs15_card *p15card;