diff --git a/prog/detect/sensors-detect b/prog/detect/sensors-detect
index 12ce62b7..2e1e6d1a 100755
--- a/prog/detect/sensors-detect
+++ b/prog/detect/sensors-detect
@@ -2546,19 +2546,30 @@ sub lm75_detect
 #        We may assume an i2c_set_slave_addr was already done.
 # $_[1]: Address
 # Returns: undef if not detected, (3) if detected,
-#   (6) or (9) if even more bits match. 
+#   (5) or (7) if even more bits match. 
 # Registers used:
+#   0xAA: Temperature
+#   0xA1: High limit
+#   0xA2: Low limit
 #   0xAC: Configuration
 # Detection is weak. We check if Bit 3 is set and Bit 2 is clear.
 # The DS1621 will aways have a config like 0x????10??. A even better
 # match would be 0x0??01000.
+# Temperature checkings will hopefully prevent LM75 chips from being
+# detected as a DS1621.
 sub ds1621_detect
 {
   my $i;
   my ($file,$addr) = @_;
+  my $temp = i2c_smbus_read_word_data($file,0xAA);
+  return if ($temp & 0x007F);
+  $temp = i2c_smbus_read_word_data($file,0xA1);
+  return if ($temp & 0x007F);
+  $temp = i2c_smbus_read_word_data($file,0xA2);
+  return if ($temp & 0x007F);
   my $conf = i2c_smbus_read_byte_data($file,0xAC);
-  return (9) if ($conf & 0x9F) == 0x98;
-  return (6) if ($conf & 0x0F) == 0x08;
+  return (7) if ($conf & 0x9F) == 0x98;
+  return (5) if ($conf & 0x0F) == 0x08;
   return (3) if ($conf & 0x0C) == 0x08;
   return ;
 }