diff --git a/libraries/AP_HAL_Linux/Poller.h b/libraries/AP_HAL_Linux/Poller.h
index 26b1c0bce2..e9dcba04d5 100644
--- a/libraries/AP_HAL_Linux/Poller.h
+++ b/libraries/AP_HAL_Linux/Poller.h
@@ -30,7 +30,7 @@ class Pollable {
     friend class Poller;
 public:
     Pollable(int fd) : _fd(fd) { }
-    Pollable() : _fd(-1) { }
+    Pollable() { }
 
     virtual ~Pollable();
 
@@ -42,7 +42,7 @@ public:
     virtual void on_hang_up() { }
 
 protected:
-    int _fd;
+    int _fd = -1;
 };
 
 class Poller {
diff --git a/libraries/AP_HAL_Linux/PollerThread.h b/libraries/AP_HAL_Linux/PollerThread.h
index 9b40e85b07..c73ea5fe76 100644
--- a/libraries/AP_HAL_Linux/PollerThread.h
+++ b/libraries/AP_HAL_Linux/PollerThread.h
@@ -56,7 +56,7 @@ protected:
 
     PeriodicCb _cb;
     WrapperCb *_wrapper;
-    bool _removeme;
+    bool _removeme = false;
 };
 
 
@@ -76,7 +76,7 @@ protected:
     void _cleanup_timers();
 
     Poller _poller{};
-    std::vector<TimerPollable*> _timers;
+    std::vector<TimerPollable*> _timers{};
 };
 
 }
diff --git a/libraries/AP_HAL_Linux/Thread.cpp b/libraries/AP_HAL_Linux/Thread.cpp
index ed26c4f168..8127c49e98 100644
--- a/libraries/AP_HAL_Linux/Thread.cpp
+++ b/libraries/AP_HAL_Linux/Thread.cpp
@@ -229,6 +229,10 @@ bool Thread::set_stack_size(size_t stack_size)
 
 bool PeriodicThread::_run()
 {
+    if (_period_usec == 0) {
+        return false;
+    }
+
     uint64_t next_run_usec = AP_HAL::micros64() + _period_usec;
 
     while (true) {
diff --git a/libraries/AP_HAL_Linux/Thread.h b/libraries/AP_HAL_Linux/Thread.h
index db8475fa07..ccf2ebfb73 100644
--- a/libraries/AP_HAL_Linux/Thread.h
+++ b/libraries/AP_HAL_Linux/Thread.h
@@ -58,15 +58,15 @@ protected:
     void _poison_stack();
 
     task_t _task;
-    bool _started;
-    pthread_t _ctx;
+    bool _started = false;
+    pthread_t _ctx = 0;
 
     struct stack_debug {
         uint32_t *start;
         uint32_t *end;
     } _stack_debug;
 
-    size_t _stack_size;
+    size_t _stack_size = 0;
 };
 
 class PeriodicThread : public Thread {
@@ -80,7 +80,7 @@ public:
 protected:
     bool _run() override;
 
-    uint64_t _period_usec;
+    uint64_t _period_usec = 0;
 };
 
 }