diff --git a/gpio-util/gpio.cpp b/gpio-util/gpio.cpp
index d5c2ce4..080ab99 100644
--- a/gpio-util/gpio.cpp
+++ b/gpio-util/gpio.cpp
@@ -58,7 +58,7 @@
     {
         auto e = errno;
         log<level::ERR>("Failed opening GPIO device",
-                        entry("DEVICE=%s", device),
+                        entry("DEVICE=%s", device.c_str()),
                         entry("ERRNO=%d", e));
         throw std::runtime_error("Failed opening GPIO device");
     }
diff --git a/presence/gpio_presence.cpp b/presence/gpio_presence.cpp
index ecc4813..4a11d98 100644
--- a/presence/gpio_presence.cpp
+++ b/presence/gpio_presence.cpp
@@ -158,7 +158,7 @@
 
     log<level::INFO>("Updating inventory present property",
                      entry("PRESENT=%d", present),
-                     entry("PATH=%s", inventory));
+                     entry("PATH=%s", inventory.c_str()));
 
     auto invService = getService(INVENTORY_PATH, INVENTORY_INTF, bus);