diff --git a/src/add-ons/kernel/busses/scsi/ahci/ahci_controller.cpp b/src/add-ons/kernel/busses/scsi/ahci/ahci_controller.cpp
index 6dea1ffd61..58d30bdc5a 100644
--- a/src/add-ons/kernel/busses/scsi/ahci/ahci_controller.cpp
+++ b/src/add-ons/kernel/busses/scsi/ahci/ahci_controller.cpp
@@ -11,6 +11,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <new>
+#include <util/BitUtils.h>
 
 #define TRACE(a...) dprintf("ahci: " a)
 #define FLOW(a...)	dprintf("ahci: " a)
@@ -335,7 +336,8 @@ AHCIController::ResetController()
 	if (fPCIVendorID == PCI_VENDOR_INTEL) {
 		// Intel PCS—Port Control and Status
 		// SATA port enable bits must be set
-		int portCount = std::max(fls(fRegs->pi), 1 + (int)((fRegs->cap >> CAP_NP_SHIFT) & CAP_NP_MASK));
+		int portCount = std::max((int)fls(fRegs->pi),
+			1 + (int)((fRegs->cap >> CAP_NP_SHIFT) & CAP_NP_MASK));
 		if (portCount > 8) {
 			// TODO: fix this when specification available
 			TRACE("don't know how to enable SATA ports 9 to %d\n", portCount);
diff --git a/src/add-ons/kernel/busses/scsi/ahci/util.cpp b/src/add-ons/kernel/busses/scsi/ahci/util.cpp
index 4a0e64dc43..2c29d56b8b 100644
--- a/src/add-ons/kernel/busses/scsi/ahci/util.cpp
+++ b/src/add-ons/kernel/busses/scsi/ahci/util.cpp
@@ -126,17 +126,3 @@ swap_words(void *data, size_t size)
 		word++;
 	}
 }
-
-
-int
-fls(unsigned mask)
-{
-	if (mask == 0)
-		return 0;
-	int pos = 1;
-	while (mask != 1) {
-		mask >>= 1;
-		pos++;
-	}
-	return pos;
-}
diff --git a/src/add-ons/kernel/busses/scsi/ahci/util.h b/src/add-ons/kernel/busses/scsi/ahci/util.h
index 75b4f9dd45..94fc1ac94c 100644
--- a/src/add-ons/kernel/busses/scsi/ahci/util.h
+++ b/src/add-ons/kernel/busses/scsi/ahci/util.h
@@ -20,8 +20,6 @@ status_t sg_memcpy(const physical_entry *sgTable, int sgCount, const void *data,
 
 void swap_words(void *data, size_t size);
 
-int fls(unsigned mask);
-
 #ifdef __cplusplus
 }
 #endif