diff --git a/configure.in b/configure.in
index cbd09992..74f532af 100644
--- a/configure.in
+++ b/configure.in
@@ -201,6 +201,7 @@ AC_CHECK_HEADERS(sys/utsname.h)
 AC_CHECK_HEADERS(stdint.h inttypes.h)
 AC_CHECK_HEADERS(locale.h pwd.h)
 AC_CHECK_HEADERS(termios.h)
+AC_CHECK_HEADERS(sys/ipc.h sys/sem.h sys/shm.h)
 
 AC_CHECK_HEADERS(sys/epoll.h, [HAVE_SYS_EPOLL_H=yes])
 
diff --git a/src/main/main.c b/src/main/main.c
index bf6eda98..05067e03 100644
--- a/src/main/main.c
+++ b/src/main/main.c
@@ -54,7 +54,9 @@
 #include "util/file.h"
 #include "util/memdebug.h"
 #include "util/memory.h"
+#if defined(HAVE_SYS_IPC_H) && defined(HAVE_SYS_SEM_H) && defined(HAVE_SYS_SHM_H)
 #include "util/sem.h"
+#endif
 #include "viewer/dump/dump.h"
 #include "viewer/text/festival.h"
 #include "viewer/text/marks.h"
@@ -115,6 +117,7 @@ check_cwd(void)
 static void
 init_master_ipc(void)
 {
+#if defined(HAVE_SYS_IPC_H) && defined(HAVE_SYS_SEM_H) && defined(HAVE_SYS_SHM_H)
 	struct string filename;
 	key_t k1, k2, k3;
 
@@ -132,11 +135,13 @@ init_master_ipc(void)
 		shared_mem = shmat(shared_mem_ipc, NULL, 0);
 	}
 	done_string(&filename);
+#endif
 }
 
 static void
 init_slave_ipc(void)
 {
+#if defined(HAVE_SYS_IPC_H) && defined(HAVE_SYS_SEM_H) && defined(HAVE_SYS_SHM_H)
 	struct string filename;
 	key_t k1, k2, k3;
 
@@ -152,11 +157,13 @@ init_slave_ipc(void)
 		shared_mem = shmat(shared_mem_ipc, NULL, 0);
 	}
 	done_string(&filename);
+#endif
 }
 
 static void
 done_ipc(void)
 {
+#if defined(HAVE_SYS_IPC_H) && defined(HAVE_SYS_SEM_H) && defined(HAVE_SYS_SHM_H)
 	if (shared_mem)
 		shmdt(shared_mem);
 	if (master_sem >= 0)
@@ -164,6 +171,7 @@ done_ipc(void)
 	if (slave_sem >= 0)
 		sem_close(slave_sem);
 	/* shared_mem_ipc will be automatically done by sem_close() */
+#endif
 }
 
 static void
diff --git a/src/mime/backend/mailcap.c b/src/mime/backend/mailcap.c
index 257cfbdd..028f52d4 100644
--- a/src/mime/backend/mailcap.c
+++ b/src/mime/backend/mailcap.c
@@ -41,7 +41,9 @@
 #include "util/hash.h"
 #include "util/lists.h"
 #include "util/memory.h"
+#if defined(HAVE_SYS_IPC_H) && defined(HAVE_SYS_SEM_H) && defined(HAVE_SYS_SHM_H)
 #include "util/sem.h"
+#endif
 #include "util/string.h"
 
 extern int master_sem;
@@ -671,11 +673,11 @@ get_mime_handler_mailcap_common(unsigned char *type)
 static struct mime_handler *
 get_mime_handler_mailcap(unsigned char *type, struct terminal *term)
 {
-	struct mime_handler *handler;
+	struct mime_handler *handler = NULL;
 	unsigned char *desc, *data;
 	int block, len;
 
-	if (!term || term->master)
+	if (!term || term->master || slave_sem == -1)
 		return get_mime_handler_mailcap_common(type);
 
 	len = strlen(type) + 1;
@@ -687,16 +689,20 @@ get_mime_handler_mailcap(unsigned char *type, struct terminal *term)
 	memcpy(data + 2, type, len);
 	hard_write(term->fdout, data, len + 2);
 	fmem_free(data);
-
+#if defined(HAVE_SYS_IPC_H) && defined(HAVE_SYS_SEM_H) && defined(HAVE_SYS_SHM_H)
+	if (!shared_mem)
+		return NULL;
+	shared_mem[0] = '\0'; /* For unexpected death of slave. */
 	sem_signal(slave_sem);
 	sem_wait(master_sem);
-	if (!shared_mem || !*shared_mem)
+	if (!*shared_mem)
 		return NULL;
 	desc = strchr(shared_mem, '\0') + 1;
 	block = (shared_mem[4095] > 0);
 	handler = init_mime_handler(shared_mem, desc, mailcap_mime_module.name,
 				    get_mailcap_ask(), block);
 	if (handler) handler->copiousoutput = shared_mem[4095] & 1;
+#endif
 	return handler;
 }
 
@@ -704,6 +710,7 @@ get_mime_handler_mailcap(unsigned char *type, struct terminal *term)
 void
 get_slave_mailcap(unsigned char *type)
 {
+#if defined(HAVE_SYS_IPC_H) && defined(HAVE_SYS_SEM_H) && defined(HAVE_SYS_SHM_H)
 	sem_wait(slave_sem);
 	if (shared_mem) {
 		struct mailcap_entry *entry;
@@ -748,6 +755,7 @@ get_slave_mailcap(unsigned char *type)
 	}
 end:
 	sem_signal(master_sem);
+#endif
 }
 
 const struct mime_backend mailcap_mime_backend = {
diff --git a/src/terminal/kbd.c b/src/terminal/kbd.c
index a72e8c8a..d086fa93 100644
--- a/src/terminal/kbd.c
+++ b/src/terminal/kbd.c
@@ -563,7 +563,9 @@ has_nul_byte:
 
 	if (fg == 3) {
 		/* Mailcap */
+#ifdef CONFIG_MAILCAP
 		get_slave_mailcap(path.source);
+#endif
 		goto next_round;
 	}
 
diff --git a/src/util/sem.c b/src/util/sem.c
index 51aaa41f..3acafcd9 100644
--- a/src/util/sem.c
+++ b/src/util/sem.c
@@ -26,6 +26,7 @@ or use of these programs.
 
 #include "elinks.h"
 
+#if defined(HAVE_SYS_IPC_H) && defined(HAVE_SYS_SEM_H) && defined(HAVE_SYS_SHM_H)
 #include "util/sem.h"
 
 extern int shared_mem_ipc;
@@ -311,3 +312,4 @@ sem_op(int id, int value)
 	semop(id, &op_op[0], 1);
 		/* err_sys("sem_op error"); */
 }
+#endif