diff --git a/configure.in b/configure.in
index ff85e701a..3b4f98958 100644
--- a/configure.in
+++ b/configure.in
@@ -210,7 +210,6 @@ 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 12c6a5ca5..89a059a6b 100644
--- a/src/main/main.c
+++ b/src/main/main.c
@@ -54,9 +54,7 @@
 #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"
@@ -117,7 +115,6 @@ 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;
 
@@ -135,13 +132,11 @@ 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;
 
@@ -157,13 +152,11 @@ 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)
@@ -171,7 +164,6 @@ 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 6964d7c86..023e676b4 100644
--- a/src/mime/backend/mailcap.c
+++ b/src/mime/backend/mailcap.c
@@ -41,9 +41,7 @@
 #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;
@@ -673,11 +671,11 @@ 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 = NULL;
+	struct mime_handler *handler;
 	unsigned char *desc, *data;
 	int block, len;
 
-	if (!term || term->master || slave_sem == -1)
+	if (!term || term->master)
 		return get_mime_handler_mailcap_common(type);
 
 	len = strlen(type) + 1;
@@ -689,20 +687,16 @@ 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)
+	if (!shared_mem || !*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;
 }
 
@@ -710,7 +704,6 @@ 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;
@@ -755,7 +748,6 @@ 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 e03337736..9875a5ed0 100644
--- a/src/terminal/kbd.c
+++ b/src/terminal/kbd.c
@@ -567,9 +567,7 @@ 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 3acafcd95..51aaa41f9 100644
--- a/src/util/sem.c
+++ b/src/util/sem.c
@@ -26,7 +26,6 @@ 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;
@@ -312,4 +311,3 @@ sem_op(int id, int value)
 	semop(id, &op_op[0], 1);
 		/* err_sys("sem_op error"); */
 }
-#endif