diff --git a/lib/bb/runqueue.py b/lib/bb/runqueue.py
index 3462ed4457..bee315c36d 100644
--- a/lib/bb/runqueue.py
+++ b/lib/bb/runqueue.py
@@ -128,6 +128,7 @@ class RunQueueStats:
 # runQueue state machine
 runQueuePrepare = 2
 runQueueSceneInit = 3
+runQueueDumpSigs = 4
 runQueueRunning = 6
 runQueueFailed = 7
 runQueueCleanUp = 8
@@ -1588,13 +1589,18 @@ class RunQueue:
             self.rqdata.init_progress_reporter.next_stage()
             self.rqexe = RunQueueExecute(self)
 
-            dump = self.cooker.configuration.dump_signatures
-            if dump:
+            dumpsigs = self.cooker.configuration.dump_signatures
+            if dumpsigs:
                 self.rqdata.init_progress_reporter.finish()
-                if 'printdiff' in dump:
+                if 'printdiff' in dumpsigs:
                     invalidtasks = self.print_diffscenetasks()
-                self.dump_signatures(dump)
-                if 'printdiff' in dump:
+                self.state = runQueueDumpSigs
+
+        if self.state is runQueueDumpSigs:
+            dumpsigs = self.cooker.configuration.dump_signatures
+            retval = self.dump_signatures(dumpsigs)
+            if retval is False:
+                if 'printdiff' in dumpsigs:
                     self.write_diffscenetasks(invalidtasks)
                 self.state = runQueueComplete
 
@@ -1686,33 +1692,42 @@ class RunQueue:
             bb.parse.siggen.dump_sigtask(taskfn, taskname, dataCaches[mc].stamp[taskfn], True)
 
     def dump_signatures(self, options):
-        if bb.cooker.CookerFeatures.RECIPE_SIGGEN_INFO not in self.cooker.featureset:
-            bb.fatal("The dump signatures functionality needs the RECIPE_SIGGEN_INFO feature enabled")
-
-        bb.note("Writing task signature files")
-
-        max_process = int(self.cfgData.getVar("BB_NUMBER_PARSE_THREADS") or os.cpu_count() or 1)
-        def chunkify(l, n):
-            return [l[i::n] for i in range(n)]
-        tids = chunkify(list(self.rqdata.runtaskentries), max_process)
-        # We cannot use the real multiprocessing.Pool easily due to some local data
-        # that can't be pickled. This is a cheap multi-process solution.
-        launched = []
-        while tids:
-            if len(launched) < max_process:
-                p = Process(target=self._rq_dump_sigtid, args=(tids.pop(), ))
+        if not hasattr(self, "dumpsigs_launched"):
+            if bb.cooker.CookerFeatures.RECIPE_SIGGEN_INFO not in self.cooker.featureset:
+                bb.fatal("The dump signatures functionality needs the RECIPE_SIGGEN_INFO feature enabled")
+
+            bb.note("Writing task signature files")
+
+            max_process = int(self.cfgData.getVar("BB_NUMBER_PARSE_THREADS") or os.cpu_count() or 1)
+            def chunkify(l, n):
+                return [l[i::n] for i in range(n)]
+            dumpsigs_tids = chunkify(list(self.rqdata.runtaskentries), max_process)
+
+            # We cannot use the real multiprocessing.Pool easily due to some local data
+            # that can't be pickled. This is a cheap multi-process solution.
+            self.dumpsigs_launched = []
+
+            for tid in dumpsigs_tids:
+                p = Process(target=self._rq_dump_sigtid, args=(dumpsigs_tids.pop(), ))
                 p.start()
-                launched.append(p)
-            for q in launched:
-                # The finished processes are joined when calling is_alive()
-                if not q.is_alive():
-                    launched.remove(q)
-        for p in launched:
+                self.dumpsigs_launched.append(p)
+
+            return 1.0
+
+        for q in self.dumpsigs_launched:
+            # The finished processes are joined when calling is_alive()
+            if not q.is_alive():
+                self.dumpsigs_launched.remove(q)
+
+        if self.dumpsigs_launched:
+            return 1.0
+
+        for p in self.dumpsigs_launched:
                 p.join()
 
         bb.parse.siggen.dump_sigs(self.rqdata.dataCaches, options)
 
-        return
+        return False
 
     def print_diffscenetasks(self):
         def get_root_invalid_tasks(task, taskdepends, valid, noexec, visited_invalid):