diff --git a/automotive/can/1.0/tools/canhalctrl.cpp b/automotive/can/1.0/tools/canhalctrl.cpp
index c186b74..bf1c3b1 100644
--- a/automotive/can/1.0/tools/canhalctrl.cpp
+++ b/automotive/can/1.0/tools/canhalctrl.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <android-base/logging.h>
+#include <android-base/parseint.h>
 #include <android/hardware/automotive/can/1.0/ICanController.h>
 #include <android/hidl/manager/1.2/IServiceManager.h>
 #include <hidl-utils/hidl-utils.h>
@@ -72,8 +73,8 @@
             slcan.ttyname(interface);
             config.interfaceId.slcan(slcan);
         } else if (type == ICanController::InterfaceType::INDEXED) {
-            auto idx = std::stol(interface);
-            if (idx < 0 || idx > UINT8_MAX) {
+            unsigned idx;
+            if (!android::base::ParseUint(interface, &idx, unsigned(UINT8_MAX))) {
                 std::cerr << "Interface index out of range: " << idx;
                 return -1;
             }
@@ -146,9 +147,11 @@
             return -1;
         }
 
-        long long bitrate = 0;
-        if (argc == 4) {
-            bitrate = std::stoll(argv[3]);
+        uint32_t bitrate = 0;
+        if (argc == 4 && !android::base::ParseUint(argv[3], &bitrate)) {
+            std::cerr << "Invalid bitrate!" << std::endl;
+            usage();
+            return -1;
         }
 
         return up(busName, *type, interface, bitrate);
diff --git a/automotive/can/1.0/tools/canhalsend.cpp b/automotive/can/1.0/tools/canhalsend.cpp
index 18e815d..f0f9d10 100644
--- a/automotive/can/1.0/tools/canhalsend.cpp
+++ b/automotive/can/1.0/tools/canhalsend.cpp
@@ -77,9 +77,9 @@
     const std::string msgidStr = msg.substr(0, hashpos);
     const std::string payloadStr = msg.substr(hashpos + 1);
 
-    size_t idx = 0;
-    V1_0::CanMessageId msgid = std::stoi(msgidStr, &idx, 16);
-    if (msgidStr[idx] != '\0') return std::nullopt;
+    V1_0::CanMessageId msgid;
+    // "0x" must be prepended to msgidStr, since ParseUint doesn't accept a base argument.
+    if (!android::base::ParseUint("0x" + msgidStr, &msgid)) return std::nullopt;
 
     V1_0::CanMessage canmsg = {};
     canmsg.id = msgid;
@@ -111,8 +111,9 @@
     if (payloadStr.size() % 2 != 0) return std::nullopt;
     for (size_t i = 0; i < payloadStr.size(); i += 2) {
         std::string byteStr(payloadStr, i, 2);
-        payload.emplace_back(std::stoi(byteStr, &idx, 16));
-        if (byteStr[idx] != '\0') return std::nullopt;
+        uint8_t byteBuf;
+        if (!android::base::ParseUint("0x" + byteStr, &byteBuf)) return std::nullopt;
+        payload.emplace_back(byteBuf);
     }
     canmsg.payload = payload;