diff --git a/hwmonio.cpp b/hwmonio.cpp
index 82d1a9d..8f0acf2 100644
--- a/hwmonio.cpp
+++ b/hwmonio.cpp
@@ -150,7 +150,7 @@
                 !retries)
             {
                 // Not a retryable error or out of retries.
-#ifdef NEGATIVE_ERRNO_ON_FAIL
+#if NEGATIVE_ERRNO_ON_FAIL
                 return -rc;
 #endif
 
diff --git a/mainloop.cpp b/mainloop.cpp
index ecceee5..40c429a 100644
--- a/mainloop.cpp
+++ b/mainloop.cpp
@@ -527,7 +527,7 @@
         }
         catch (const std::system_error& e)
         {
-#ifdef UPDATE_FUNCTIONAL_ON_FAIL
+#if UPDATE_FUNCTIONAL_ON_FAIL
             // If UPDATE_FUNCTIONAL_ON_FAIL is defined and an exception was
             // thrown, set the functional property to false.
             // We cannot set this with the 'continue' in the lower block
@@ -553,7 +553,7 @@
                 }
                 continue;
             }
-#ifdef UPDATE_FUNCTIONAL_ON_FAIL
+#if UPDATE_FUNCTIONAL_ON_FAIL
             // Do not exit with failure if UPDATE_FUNCTIONAL_ON_FAIL is set
             continue;
 #endif
diff --git a/sensor.cpp b/sensor.cpp
index 09aeca6..43af2f6 100644
--- a/sensor.cpp
+++ b/sensor.cpp
@@ -96,7 +96,7 @@
 // Because read doesn't have an out pointer to store errors.
 // let's assume negative values are errors if they have this
 // set.
-#ifdef NEGATIVE_ERRNO_ON_FAIL
+#if NEGATIVE_ERRNO_ON_FAIL
     if (value < 0)
     {
         return value;
@@ -137,7 +137,7 @@
     // Only read the input value if the status is functional
     if (statusIface->functional())
     {
-#ifdef UPDATE_FUNCTIONAL_ON_FAIL
+#if UPDATE_FUNCTIONAL_ON_FAIL
         try
 #endif
         {
@@ -151,7 +151,7 @@
                                 hwmon::entry::cinput, std::get<size_t>(retryIO),
                                 std::get<std::chrono::milliseconds>(retryIO));
         }
-#ifdef UPDATE_FUNCTIONAL_ON_FAIL
+#if UPDATE_FUNCTIONAL_ON_FAIL
         catch (const std::system_error& e)
         {
             // Catch the exception here and update the functional property.