diff --git a/Lib/idlelib/CallTipWindow.py b/Lib/idlelib/CallTipWindow.py
index afd4439a7df..22238855c16 100644
--- a/Lib/idlelib/CallTipWindow.py
+++ b/Lib/idlelib/CallTipWindow.py
@@ -49,7 +49,11 @@ def showtip(self, text, parenleft, parenright):
         """
         # truncate overly long calltip
         if len(text) >= 79:
-            text = text[:75] + ' ...'
+            textlines = text.splitlines()
+            for i, line in enumerate(textlines):
+                if len(line) > 79:
+                    textlines[i] = line[:75] + ' ...'
+            text = '\n'.join(textlines)
         self.text = text
         if self.tipwindow or not self.text:
             return
diff --git a/Misc/NEWS b/Misc/NEWS
index 9cbc9e48736..afa7915b571 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -39,6 +39,8 @@ Core and builtins
 Library
 -------
 
+- Bug #1525817: Don't truncate short lines in IDLE's tool tips.
+
 - Patch #1515343: Fix printing of deprecated string exceptions with a
   value in the traceback module.