diff --git a/src/bin/psql/print.c b/src/bin/psql/print.c
index cab9e6e..5e2ff09 100644
--- a/src/bin/psql/print.c
+++ b/src/bin/psql/print.c
@@ -2725,6 +2725,12 @@ print_troff_ms_vertical(const printTableContent *cont, FILE *fout)
 /* Public functions		*/
 /********************************/
 
+#ifdef USE_ASSERT_CHECKING
+#define MAX_PAGEOUTPUT_LINES 1000
+#define MAX_PAGEOUTPUT_BUF (1000 * 80 * 2)
+static char *PageOutputBuf;
+static int expected_lines;
+#endif
 
 /*
  * PageOutput
@@ -2770,6 +2776,21 @@ PageOutput(int lines, const printTableOpt *topt)
 #endif
 	}
 
+#ifdef USE_ASSERT_CHECKING
+	if (lines < MAX_PAGEOUTPUT_LINES)
+	{
+		fflush(stdout);
+		expected_lines = lines;
+		if (!PageOutputBuf)
+		{
+			PageOutputBuf = pg_malloc0(MAX_PAGEOUTPUT_BUF);
+			setvbuf(stdout, PageOutputBuf, _IOFBF, MAX_PAGEOUTPUT_BUF);
+		} else {
+			memset(PageOutputBuf, MAX_PAGEOUTPUT_BUF, 0);
+		}
+	}
+#endif
+
 	return stdout;
 }
 
@@ -2799,6 +2820,33 @@ ClosePager(FILE *pagerpipe)
 		pqsignal(SIGPIPE, SIG_DFL);
 #endif
 	}
+
+#ifdef USE_ASSERT_CHECKING
+	if (PageOutputBuf && expected_lines)
+	{
+		int n_newlines = 0;
+		int i;
+		for (i=0;i<MAX_PAGEOUTPUT_BUF;i++)
+		{
+			if (PageOutputBuf[i]=='\n')
+			{
+				n_newlines++;
+			}
+		}
+		fprintf(stderr, "Expected %d lines, actually printed %d lines\n",
+				expected_lines, n_newlines);
+		Assert(n_newlines == expected_lines);
+
+		expected_lines = 0;
+		fflush(stdout);
+
+		/* XXX leave this set? not sure. */
+		setbuffer(stdout, NULL, 0);
+		pg_free(PageOutputBuf);
+		PageOutputBuf = 0;
+		
+	}
+#endif
 }
 
 /*