diff --git a/src/if_cscope.c b/src/if_cscope.c
index 376e2a6..0019559 100644
--- a/src/if_cscope.c
+++ b/src/if_cscope.c
@@ -2163,7 +2163,7 @@
 	    waitpid_errno = errno;
 	    if (pid != 0)
 		break;  /* break unless the process is still running */
-	    mch_delay(50, FALSE); /* sleep 50 ms */
+	    mch_delay(50L, FALSE); /* sleep 50 ms */
 	}
 # endif
 	/*
@@ -2198,7 +2198,7 @@
 			alive = FALSE; /* cscope process no longer exists */
 			break;
 		    }
-		    mch_delay(50, FALSE); /* sleep 50ms */
+		    mch_delay(50L, FALSE); /* sleep 50ms */
 		}
 	    }
 	    if (alive)