diff --git a/pci/src/configuration.rs b/pci/src/configuration.rs
index 2a905e19b..8973c3883 100644
--- a/pci/src/configuration.rs
+++ b/pci/src/configuration.rs
@@ -987,7 +987,7 @@ impl PciConfiguration {
                 return None;
             }
 
-            let bar_idx = reg_idx - 4;
+            let bar_idx = reg_idx - BAR0_REG;
             // Handle special case where the address being written is
             // different from the address initially provided. This is a
             // BAR reprogramming case which needs to be properly caught.
@@ -1025,7 +1025,7 @@ impl PciConfiguration {
                     len,
                     region_type,
                 });
-            } else if (reg_idx > BAR0_REG)
+            } else if (bar_idx > 0)
                 && ((self.registers[reg_idx - 1] & self.writable_bits[reg_idx - 1])
                     != (self.bars[bar_idx - 1].addr & self.writable_bits[reg_idx - 1])
                     || (value & mask) != (self.bars[bar_idx].addr & mask))