diff --git a/include/zephyr/posix/signal.h b/include/zephyr/posix/signal.h
index b31147306c2..c326fa948df 100644
--- a/include/zephyr/posix/signal.h
+++ b/include/zephyr/posix/signal.h
@@ -12,7 +12,6 @@
 extern "C" {
 #endif
 
-#ifdef CONFIG_POSIX_SIGNAL
 #define SIGHUP    1  /**< Hangup */
 #define SIGINT    2  /**< Interrupt */
 #define SIGQUIT   3  /**< Quit */
@@ -45,24 +44,17 @@ extern "C" {
 /* 30 not used */
 #define SIGSYS    31 /**< Bad system call */
 
+#define RTSIG_MAX CONFIG_POSIX_RTSIG_MAX
 #define SIGRTMIN 32
-#define SIGRTMAX (SIGRTMIN + CONFIG_POSIX_RTSIG_MAX)
+#define SIGRTMAX (SIGRTMIN + RTSIG_MAX)
 #define _NSIG (SIGRTMAX + 1)
 
-BUILD_ASSERT(CONFIG_POSIX_RTSIG_MAX >= 0);
+BUILD_ASSERT(RTSIG_MAX >= 0);
 
 typedef struct {
 	unsigned long sig[DIV_ROUND_UP(_NSIG, BITS_PER_LONG)];
 } sigset_t;
 
-char *strsignal(int signum);
-int sigemptyset(sigset_t *set);
-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
 #endif
@@ -90,6 +82,15 @@ struct sigevent {
 	pthread_attr_t *sigev_notify_attributes;
 };
 
+#ifdef CONFIG_POSIX_SIGNAL
+char *strsignal(int signum);
+int sigemptyset(sigset_t *set);
+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 */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/posix/Kconfig.signal b/lib/posix/Kconfig.signal
index c51e68f1f36..4f29080c0ee 100644
--- a/lib/posix/Kconfig.signal
+++ b/lib/posix/Kconfig.signal
@@ -9,12 +9,6 @@ config POSIX_SIGNAL
 	  Enable support for POSIX signal APIs.
 
 if POSIX_SIGNAL
-config POSIX_RTSIG_MAX
-	int "Maximum number of realtime signals"
-	default 31
-	help
-	  Define the maximum number of realtime signals (RTSIG_MAX).
-	  The range of realtime signals is [SIGRTMIN .. (SIGRTMIN+RTSIG_MAX)]
 
 config POSIX_SIGNAL_STRING_DESC
 	bool "Use full description for the strsignal API"
@@ -24,3 +18,12 @@ config POSIX_SIGNAL_STRING_DESC
 	  Will use 256 bytes of ROM.
 
 endif
+
+# needed outside of if clause above to define constants & types in signal.h
+config POSIX_RTSIG_MAX
+	int "Maximum number of realtime signals"
+	default 31 if POSIX_SIGNAL
+	default 0 if !POSIX_SIGNAL
+	help
+	  Define the maximum number of realtime signals (RTSIG_MAX).
+	  The range of realtime signals is [SIGRTMIN .. (SIGRTMIN+RTSIG_MAX)]