diff --git a/include/zephyr/posix/posix_types.h b/include/zephyr/posix/posix_types.h
index fbfc976d6fb976..0f3e0319e30d24 100644
--- a/include/zephyr/posix/posix_types.h
+++ b/include/zephyr/posix/posix_types.h
@@ -35,7 +35,6 @@ typedef uint32_t clockid_t;
 typedef unsigned long timer_t;
 #endif
 
-#ifdef CONFIG_PTHREAD_IPC
 /* Thread attributes */
 struct pthread_attr {
 	int priority;
@@ -101,8 +100,6 @@ typedef struct pthread_rwlock_obj {
 	k_tid_t wr_owner;
 } pthread_rwlock_t;
 
-#endif /* CONFIG_PTHREAD_IPC */
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/zephyr/posix/signal.h b/include/zephyr/posix/signal.h
index 0cfa5649b387cf..86b37c8b710da6 100644
--- a/include/zephyr/posix/signal.h
+++ b/include/zephyr/posix/signal.h
@@ -8,11 +8,10 @@
 
 #include "posix_types.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
+#define SIG_DFL ((sighandler_t)0)
+#define SIG_ERR ((sighandler_t)1)
+#define SIG_IGN ((sighandler_t)-1)
 
-#ifdef CONFIG_POSIX_SIGNAL
 #define SIGHUP    1  /**< Hangup */
 #define SIGINT    2  /**< Interrupt */
 #define SIGQUIT   3  /**< Quit */
@@ -51,6 +50,10 @@ extern "C" {
 
 BUILD_ASSERT(CONFIG_POSIX_RTSIG_MAX >= 0);
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct {
 	unsigned long sig[DIV_ROUND_UP(_NSIG, BITS_PER_LONG)];
 } sigset_t;
@@ -61,7 +64,6 @@ int sigfillset(sigset_t *set);
 int sigaddset(sigset_t *set, int signo);
 int sigdelset(sigset_t *set, int signo);
 int sigismember(const sigset_t *set, int signo);
-#endif /* CONFIG_POSIX_SIGNAL */
 
 #ifndef SIGEV_NONE
 #define SIGEV_NONE 1
@@ -92,6 +94,9 @@ typedef struct sigevent {
 	#endif
 } sigevent;
 
+typedef void (*sighandler_t)(int signo);
+sighandler_t signal(int signum, sighandler_t handler);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/libc/minimal/CMakeLists.txt b/lib/libc/minimal/CMakeLists.txt
index 71a404e7870926..61f7a48ff804bd 100644
--- a/lib/libc/minimal/CMakeLists.txt
+++ b/lib/libc/minimal/CMakeLists.txt
@@ -10,6 +10,7 @@ set(STRERROR_TABLE_H ${GEN_DIR}/libc/minimal/strerror_table.h)
 zephyr_library_cc_option(-fno-builtin)
 
 zephyr_library_sources(
+  source/signal/signal.c
   source/stdlib/atoi.c
   source/stdlib/strtol.c
   source/stdlib/strtoul.c
diff --git a/lib/libc/minimal/include/signal.h b/lib/libc/minimal/include/signal.h
new file mode 100644
index 00000000000000..f465db67d87572
--- /dev/null
+++ b/lib/libc/minimal/include/signal.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2023 Meta
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_LIB_LIBC_MINIMAL_INCLUDE_SIGNAL_H_
+#define ZEPHYR_LIB_LIBC_MINIMAL_INCLUDE_SIGNAL_H_
+
+#define SIG_DFL ((sighandler_t)0)
+#define SIG_ERR ((sighandler_t)1)
+#define SIG_IGN ((sighandler_t)-1)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef int	sig_atomic_t;		/* Atomic entity type (ANSI) */
+
+/* Note: sighandler_t is a gnu-ism, but it simplifies the declaration below */
+typedef void (*sighandler_t)(int signo);
+
+sighandler_t signal(int signum, sighandler_t handler);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* ZEPHYR_LIB_LIBC_MINIMAL_INCLUDE_SIGNAL_H_ */
diff --git a/lib/libc/minimal/source/signal/signal.c b/lib/libc/minimal/source/signal/signal.c
new file mode 100644
index 00000000000000..eb371ab652fd0c
--- /dev/null
+++ b/lib/libc/minimal/source/signal/signal.c
@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2023 Meta
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <signal.h>
+
+sighandler_t signal(int signum, sighandler_t handler)
+{
+	return SIG_DFL;
+}
diff --git a/lib/posix/Kconfig.signal b/lib/posix/Kconfig.signal
index c51e68f1f36a49..7e50bf0515bf9f 100644
--- a/lib/posix/Kconfig.signal
+++ b/lib/posix/Kconfig.signal
@@ -8,7 +8,6 @@ config POSIX_SIGNAL
 	help
 	  Enable support for POSIX signal APIs.
 
-if POSIX_SIGNAL
 config POSIX_RTSIG_MAX
 	int "Maximum number of realtime signals"
 	default 31
@@ -16,6 +15,8 @@ config POSIX_RTSIG_MAX
 	  Define the maximum number of realtime signals (RTSIG_MAX).
 	  The range of realtime signals is [SIGRTMIN .. (SIGRTMIN+RTSIG_MAX)]
 
+if POSIX_SIGNAL
+
 config POSIX_SIGNAL_STRING_DESC
 	bool "Use full description for the strsignal API"
 	default y
diff --git a/lib/posix/Kconfig.timer b/lib/posix/Kconfig.timer
index 28173692e0ce84..b904d942a88962 100644
--- a/lib/posix/Kconfig.timer
+++ b/lib/posix/Kconfig.timer
@@ -7,6 +7,10 @@ type = timer_t
 type-function = timer_create
 source "lib/posix/Kconfig.template.pooled_type"
 
+config POSIX_TIMER
+	bool
+	imply POSIX_SIGNAL
+
 config TIMER_CREATE_WAIT
 	int "Time to wait for timer availability (in msec) in POSIX application"
 	default 100
diff --git a/lib/posix/signal.c b/lib/posix/signal.c
index d2153238ff8fc5..6bf65c7373d301 100644
--- a/lib/posix/signal.c
+++ b/lib/posix/signal.c
@@ -10,6 +10,8 @@
 
 #include <zephyr/posix/signal.h>
 
+BUILD_ASSERT(CONFIG_POSIX_RTSIG_MAX >= 0);
+
 #define SIGNO_WORD_IDX(_signo) (signo / BITS_PER_LONG)
 #define SIGNO_WORD_BIT(_signo) (signo & BIT_MASK(LOG2(BITS_PER_LONG)))
 
diff --git a/tests/lib/c_lib/src/test_signal_decl.c b/tests/lib/c_lib/src/test_signal_decl.c
new file mode 100644
index 00000000000000..fa9490f911df5d
--- /dev/null
+++ b/tests/lib/c_lib/src/test_signal_decl.c
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2023 Meta
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <signal.h>
+
+#include <zephyr/ztest.h>
+
+ZTEST(test_c_lib, test_signal_decl)
+{
+	/*
+	 * Even though the use of the ANSI-C function "signal()" is not yet
+	 * supported in Zephyr, some users depend on it being declared (i.e.
+	 * without CONFIG_POSIX_API=y and with with CONFIG_POSIX_SIGNAL=n).
+	 */
+
+	zassert_not_null(signal);
+}
diff --git a/tests/posix/headers/prj.conf b/tests/posix/headers/prj.conf
index 43b6bc147c46c3..1005d7f577c38f 100644
--- a/tests/posix/headers/prj.conf
+++ b/tests/posix/headers/prj.conf
@@ -18,3 +18,4 @@ CONFIG_POSIX_CLOCK=y
 CONFIG_POSIX_MQUEUE=y
 CONFIG_EVENTFD=y
 CONFIG_GETOPT=y
+CONFIG_POSIX_SIGNAL=y
diff --git a/tests/posix/headers/src/signal_h.c b/tests/posix/headers/src/signal_h.c
index 852cddf3df0f83..3b34d5a039a394 100644
--- a/tests/posix/headers/src/signal_h.c
+++ b/tests/posix/headers/src/signal_h.c
@@ -19,12 +19,17 @@
  */
 ZTEST(posix_headers, test_signal_h)
 {
+	/* part of ANSI C */
+	zassert_not_null(signal);
+	/* part of ISO C */
+	zassert_not_equal(sizeof(sig_atomic_t), 0);
+
+#ifdef CONFIG_POSIX_API
 	/* zassert_not_equal(-1, SIG_DFL); */ /* not implemented */
 	/* zassert_not_equal(-1, SIG_ERR); */ /* not implemented */
 	/* zassert_not_equal(-1, SIG_HOLD); */ /* not implemented */
 	/* zassert_not_equal(-1, SIG_IGN); */ /* not implemented */
 
-	/* zassert_not_equal((sig_atomic_t)-1, (sig_atomic_t)0); */ /* not implemented */
 	/* zassert_not_equal((pid_t)-1, (pid_t)0); */ /* not implemented */
 
 	zassert_not_equal(-1, offsetof(struct sigevent, sigev_notify));
@@ -130,7 +135,6 @@ ZTEST(posix_headers, test_signal_h)
 	/* zassert_not_equal(-1, SI_ASYNCIO); */ /* not implemented */
 	/* zassert_not_equal(-1, SI_MESGQ); */ /* not implemented */
 
-#ifdef CONFIG_POSIX_SIGNAL
 	zassert_true(SIGRTMIN >= 0);
 	zassert_true(SIGRTMAX >= SIGRTMIN);
 	zassert_not_equal(-1, SIGABRT);
@@ -157,38 +161,34 @@ ZTEST(posix_headers, test_signal_h)
 	zassert_not_equal(-1, SIGURG);
 	zassert_not_equal(-1, SIGXCPU);
 	zassert_not_equal(-1, SIGXFSZ);
-	zassert_not_equal(((sigset_t){.sig[0] = 0}).sig[0], ((sigset_t){.sig[0] = -1}).sig[0]);
+	zassert_not_equal(sizeof(sigset_t), 0);
 	zassert_not_null(sigemptyset);
 	zassert_not_null(sigfillset);
 	zassert_not_null(sigaddset);
 	zassert_not_null(sigdelset);
 	zassert_not_null(sigismember);
 	zassert_not_null(strsignal);
-#endif /* CONFIG_POSIX_SIGNAL */
-
-	if (IS_ENABLED(CONFIG_POSIX_API)) {
-		/* zassert_not_null(kill); */ /* not implemented */
-		/* zassert_not_null(killpg); */ /* not implemented */
-		/* zassert_not_null(psiginfo); */ /* not implemented */
-		/* zassert_not_null(psignal); */ /* not implemented */
-		/* zassert_not_null(pthread_kill); */ /* not implemented */
-		/* zassert_not_null(pthread_sigmask); */ /* not implemented */
-		/* zassert_not_null(raise); */ /* not implemented */
-		/* zassert_not_null(sigaction); */ /* not implemented */
-		/* zassert_not_null(sigaltstack); */ /* not implemented */
-		/* zassert_not_null(sighold); */ /* not implemented */
-		/* zassert_not_null(sigignore); */ /* not implemented */
-		/* zassert_not_null(siginterrupt); */ /* not implemented */
-		/* zassert_not_null(signal); */ /* not implemented */
-		/* zassert_not_null(sigpause); */ /* not implemented */
-		/* zassert_not_null(sigpending); */ /* not implemented */
-		/* zassert_not_null(sigprocmask); */ /* not implemented */
-		/* zassert_not_null(sigqueue); */ /* not implemented */
-		/* zassert_not_null(sigrelse); */ /* not implemented */
-		/* zassert_not_null(sigset); */ /* not implemented */
-		/* zassert_not_null(sigsuspend); */ /* not implemented */
-		/* zassert_not_null(sigtimedwait); */ /* not implemented */
-		/* zassert_not_null(sigwait); */ /* not implemented */
-		/* zassert_not_null(sigwaitinfo); */ /* not implemented */
-	}
+	/* zassert_not_null(kill); */ /* not implemented */
+	/* zassert_not_null(killpg); */ /* not implemented */
+	/* zassert_not_null(psiginfo); */ /* not implemented */
+	/* zassert_not_null(psignal); */ /* not implemented */
+	/* zassert_not_null(pthread_kill); */ /* not implemented */
+	/* zassert_not_null(pthread_sigmask); */ /* not implemented */
+	/* zassert_not_null(raise); */ /* not implemented */
+	/* zassert_not_null(sigaction); */ /* not implemented */
+	/* zassert_not_null(sigaltstack); */ /* not implemented */
+	/* zassert_not_null(sighold); */ /* not implemented */
+	/* zassert_not_null(sigignore); */ /* not implemented */
+	/* zassert_not_null(siginterrupt); */ /* not implemented */
+	/* zassert_not_null(sigpause); */ /* not implemented */
+	/* zassert_not_null(sigpending); */ /* not implemented */
+	/* zassert_not_null(sigprocmask); */ /* not implemented */
+	/* zassert_not_null(sigqueue); */ /* not implemented */
+	/* zassert_not_null(sigrelse); */ /* not implemented */
+	/* zassert_not_null(sigset); */ /* not implemented */
+	/* zassert_not_null(sigsuspend); */ /* not implemented */
+	/* zassert_not_null(sigtimedwait); */ /* not implemented */
+	/* zassert_not_null(sigwait); */ /* not implemented */
+	/* zassert_not_null(sigwaitinfo); */ /* not implemented */
+#endif
 }