diff --git a/lib/libc_r/uthread/uthread_kern.c b/lib/libc_r/uthread/uthread_kern.c
index 8a3225335c65..9d317eda6cca 100644
--- a/lib/libc_r/uthread/uthread_kern.c
+++ b/lib/libc_r/uthread/uthread_kern.c
@@ -206,12 +206,6 @@ _thread_kern_scheduler(void)
 			PANIC("Unable to restore alternate signal stack");
 	}
 
-	/* Are there pending signals for this thread? */
-	if (curthread->check_pending != 0) {
-		curthread->check_pending = 0;
-		_thread_sig_check_pending(curthread);
-	}
-
 	/*
 	 * Enter a scheduling loop that finds the next thread that is
 	 * ready to run. This loop completes when there are no more threads
@@ -335,6 +329,21 @@ _thread_kern_scheduler(void)
 				PTHREAD_WORKQ_INSERT(curthread);
 				break;
 			}
+
+			/*
+			 * Are there pending signals for this thread?
+			 *
+			 * This check has to be performed after the thread
+			 * has been placed in the queue(s) appropriate for
+			 * its state.  The process of adding pending signals
+			 * can change a threads state, which in turn will
+			 * attempt to add or remove the thread from any
+			 * scheduling queue to which it belongs.
+			 */
+			if (curthread->check_pending != 0) {
+				curthread->check_pending = 0;
+				_thread_sig_check_pending(curthread);
+			}
 		}
 
 		/*
diff --git a/lib/libc_r/uthread/uthread_sig.c b/lib/libc_r/uthread/uthread_sig.c
index 71a88efe4a30..9ce53a0c702c 100644
--- a/lib/libc_r/uthread/uthread_sig.c
+++ b/lib/libc_r/uthread/uthread_sig.c
@@ -575,6 +575,9 @@ thread_sig_add(pthread_t pthread, int sig, int has_args)
 
 	restart = _thread_sigact[sig - 1].sa_flags & SA_RESTART;
 
+	/* Make sure this signal isn't still in the pending set: */
+	sigdelset(&pthread->sigpend, sig);
+
 	/*
 	 * Process according to thread state:
 	 */
diff --git a/lib/libkse/thread/thr_kern.c b/lib/libkse/thread/thr_kern.c
index 8a3225335c65..9d317eda6cca 100644
--- a/lib/libkse/thread/thr_kern.c
+++ b/lib/libkse/thread/thr_kern.c
@@ -206,12 +206,6 @@ _thread_kern_scheduler(void)
 			PANIC("Unable to restore alternate signal stack");
 	}
 
-	/* Are there pending signals for this thread? */
-	if (curthread->check_pending != 0) {
-		curthread->check_pending = 0;
-		_thread_sig_check_pending(curthread);
-	}
-
 	/*
 	 * Enter a scheduling loop that finds the next thread that is
 	 * ready to run. This loop completes when there are no more threads
@@ -335,6 +329,21 @@ _thread_kern_scheduler(void)
 				PTHREAD_WORKQ_INSERT(curthread);
 				break;
 			}
+
+			/*
+			 * Are there pending signals for this thread?
+			 *
+			 * This check has to be performed after the thread
+			 * has been placed in the queue(s) appropriate for
+			 * its state.  The process of adding pending signals
+			 * can change a threads state, which in turn will
+			 * attempt to add or remove the thread from any
+			 * scheduling queue to which it belongs.
+			 */
+			if (curthread->check_pending != 0) {
+				curthread->check_pending = 0;
+				_thread_sig_check_pending(curthread);
+			}
 		}
 
 		/*
diff --git a/lib/libkse/thread/thr_sig.c b/lib/libkse/thread/thr_sig.c
index 71a88efe4a30..9ce53a0c702c 100644
--- a/lib/libkse/thread/thr_sig.c
+++ b/lib/libkse/thread/thr_sig.c
@@ -575,6 +575,9 @@ thread_sig_add(pthread_t pthread, int sig, int has_args)
 
 	restart = _thread_sigact[sig - 1].sa_flags & SA_RESTART;
 
+	/* Make sure this signal isn't still in the pending set: */
+	sigdelset(&pthread->sigpend, sig);
+
 	/*
 	 * Process according to thread state:
 	 */
diff --git a/lib/libpthread/thread/thr_kern.c b/lib/libpthread/thread/thr_kern.c
index 8a3225335c65..9d317eda6cca 100644
--- a/lib/libpthread/thread/thr_kern.c
+++ b/lib/libpthread/thread/thr_kern.c
@@ -206,12 +206,6 @@ _thread_kern_scheduler(void)
 			PANIC("Unable to restore alternate signal stack");
 	}
 
-	/* Are there pending signals for this thread? */
-	if (curthread->check_pending != 0) {
-		curthread->check_pending = 0;
-		_thread_sig_check_pending(curthread);
-	}
-
 	/*
 	 * Enter a scheduling loop that finds the next thread that is
 	 * ready to run. This loop completes when there are no more threads
@@ -335,6 +329,21 @@ _thread_kern_scheduler(void)
 				PTHREAD_WORKQ_INSERT(curthread);
 				break;
 			}
+
+			/*
+			 * Are there pending signals for this thread?
+			 *
+			 * This check has to be performed after the thread
+			 * has been placed in the queue(s) appropriate for
+			 * its state.  The process of adding pending signals
+			 * can change a threads state, which in turn will
+			 * attempt to add or remove the thread from any
+			 * scheduling queue to which it belongs.
+			 */
+			if (curthread->check_pending != 0) {
+				curthread->check_pending = 0;
+				_thread_sig_check_pending(curthread);
+			}
 		}
 
 		/*
diff --git a/lib/libpthread/thread/thr_sig.c b/lib/libpthread/thread/thr_sig.c
index 71a88efe4a30..9ce53a0c702c 100644
--- a/lib/libpthread/thread/thr_sig.c
+++ b/lib/libpthread/thread/thr_sig.c
@@ -575,6 +575,9 @@ thread_sig_add(pthread_t pthread, int sig, int has_args)
 
 	restart = _thread_sigact[sig - 1].sa_flags & SA_RESTART;
 
+	/* Make sure this signal isn't still in the pending set: */
+	sigdelset(&pthread->sigpend, sig);
+
 	/*
 	 * Process according to thread state:
 	 */