diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index d948369f3e..a4b53b33cd 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -957,7 +957,15 @@ PostmasterMain(int argc, char *argv[])
 	 */
 	CreateDataDirLockFile(true);
 
-	/* read control file (error checking and contains config) */
+	/*
+	 * Read the control file (for error checking and config info).
+	 *
+	 * Since we verify the control file's CRC, this has a useful side effect
+	 * on machines where we need a run-time test for CRC support instructions.
+	 * The postmaster will do the test once at startup, and then its child
+	 * processes will inherit the correct function pointer and not need to
+	 * repeat the test.
+	 */
 	LocalProcessControlFile(false);
 
 	/*
diff --git a/src/port/pg_crc32c_armv8_choose.c b/src/port/pg_crc32c_armv8_choose.c
index d0d3a3da78..c339af7f16 100644
--- a/src/port/pg_crc32c_armv8_choose.c
+++ b/src/port/pg_crc32c_armv8_choose.c
@@ -18,11 +18,15 @@
  *-------------------------------------------------------------------------
  */
 
-#include "c.h"
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
 
 #include <setjmp.h>
+#include <signal.h>
 
-#include "libpq/pqsignal.h"
 #include "port/pg_crc32c.h"
 
 
@@ -33,7 +37,7 @@ static sigjmp_buf illegal_instruction_jump;
  * isn't available, we expect to get SIGILL, which we can trap.
  */
 static void
-illegal_instruction_handler(int signo)
+illegal_instruction_handler(SIGNAL_ARGS)
 {
 	siglongjmp(illegal_instruction_jump, 1);
 }
@@ -42,16 +46,35 @@ static bool
 pg_crc32c_armv8_available(void)
 {
 	uint64		data = 42;
-	bool		result;
+	int			result;
 
+	/*
+	 * Be careful not to do anything that might throw an error while we have
+	 * the SIGILL handler set to a nonstandard value.
+	 */
 	pqsignal(SIGILL, illegal_instruction_handler);
 	if (sigsetjmp(illegal_instruction_jump, 1) == 0)
-		result = (pg_comp_crc32c_armv8(0, &data, sizeof(data)) == 0xdd439b0d);
+	{
+		/* Rather than hard-wiring an expected result, compare to SB8 code */
+		result = (pg_comp_crc32c_armv8(0, &data, sizeof(data)) ==
+				  pg_comp_crc32c_sb8(0, &data, sizeof(data)));
+	}
 	else
-		result = false;
+	{
+		/* We got the SIGILL trap */
+		result = -1;
+	}
 	pqsignal(SIGILL, SIG_DFL);
 
-	return result;
+#ifndef FRONTEND
+	/* We don't expect this case, so complain loudly */
+	if (result == 0)
+		elog(ERROR, "crc32 hardware and software results disagree");
+
+	elog(DEBUG1, "using armv8 crc32 hardware = %d", (result > 0));
+#endif
+
+	return (result > 0);
 }
 
 /*