diff --git a/glances/glances.py b/glances/glances.py
index 47ddb196..8d2cd1ee 100755
--- a/glances/glances.py
+++ b/glances/glances.py
@@ -3640,7 +3640,7 @@ def printSyntax():
     print(_("\t-t sec\t\tSet the refresh time in seconds (default: %d)" %
             refresh_time))
     print(_("\t-v\t\tDisplay the version and exit"))
-    print(_("\t-y\t\tEnable the hddtemp module"))    
+    print(_("\t-y\t\tEnable the hddtemp module (needs running hddtemp daemon)"))    
     print(_("\t-z\t\tDo not use the bold color attribute"))
 
 
diff --git a/man/glances.1 b/man/glances.1
index ece2a83b..f89fc4e0 100644
--- a/man/glances.1
+++ b/man/glances.1
@@ -48,7 +48,7 @@ The command line options are the following:
 .PP
 	-v		Display the version and exit
 .PP
-	-y		Enable the hddtemp module
+	-y		Enable the hddtemp module (requires running hddtemp daemon)
 .PP
 	-z		Do not use the bold color attribute
 .PP