diff --git a/contrib/chkpass/chkpass.c b/contrib/chkpass/chkpass.c
index 283ad9a..b361718 100644
--- a/contrib/chkpass/chkpass.c
+++ b/contrib/chkpass/chkpass.c
@@ -75,10 +75,24 @@ chkpass_in(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_DATA_EXCEPTION),
 				 errmsg("password \"%s\" is weak", str)));
 
+#ifndef RANDOMIZE_ALLOCATED_MEMORY
 	result = (chkpass *) palloc(sizeof(chkpass));
 
 	mysalt[0] = salt_chars[random() & 0x3f];
 	mysalt[1] = salt_chars[random() & 0x3f];
+#else
+	/*
+	 * Trailing uninitialized bytes after the null character can lead to
+	 * unstable input conversion warnings in RANDOMIZE_ALLOCATED_MEMORY
+	 * enable build.
+	 */
+	result = (chkpass *) palloc0(sizeof(chkpass));
+
+	/* Instead of random salt use constant value for consistent result */
+	mysalt[0] = salt_chars[1];
+	mysalt[1] = salt_chars[2];
+#endif
+
 	mysalt[2] = 0;				/* technically the terminator is not necessary
 								 * but I like to play safe */