diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc
index 326202d295fb0d5aee28d3e2fff8d85ce4be2931..a720afd6cdd4565127c91bd0e9c9ec58146eea2b 100644
--- a/src/libmain/shared.cc
+++ b/src/libmain/shared.cc
@@ -332,11 +332,7 @@ RunPager::~RunPager()
             pid.wait();
         }
     } catch (...) {
-        try {
-            pid.kill(true);
-        } catch (...) {
-            ignoreException();
-        }
+        ignoreException();
     }
 }
 
diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 2b0f8e592d55adb1df5825cdb9bf994944098fe7..fc840df81a564c927a8ab72c4c8ed0482b12578c 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -642,7 +642,7 @@ HookInstance::~HookInstance()
 {
     try {
         toHook.writeSide = -1;
-        if (pid != -1) pid.kill(true);
+        if (pid != -1) pid.kill();
     } catch (...) {
         ignoreException();
     }
@@ -1437,7 +1437,7 @@ void DerivationGoal::buildDone()
        to have terminated.  In fact, the builder could also have
        simply have closed its end of the pipe, so just to be sure,
        kill it. */
-    int status = hook ? hook->pid.kill(true) : pid.kill(true);
+    int status = hook ? hook->pid.kill() : pid.kill();
 
     debug(format("builder process for ‘%1%’ finished") % drvPath);
 
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index d2d32782d02749315151808c82cb0ebca54642d0..99a91c8cc64a30d6dc850bc1b10a3367ebb83bbd 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -678,12 +678,11 @@ Pid::operator pid_t()
 }
 
 
-int Pid::kill(bool quiet)
+int Pid::kill()
 {
     assert(pid != -1);
 
-    if (!quiet)
-        printError(format("killing process %1%") % pid);
+    debug(format("killing process %1%") % pid);
 
     /* Send the requested signal to the child.  If it has its own
        process group, send the signal to every process in the child
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index 4e3a011b349c292bfa7c456db204fc2a97a34d44..f94c0ff1c5ee02cbf70a8c8589b700099b1c4b70 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -203,7 +203,7 @@ public:
     ~Pid();
     void operator =(pid_t pid);
     operator pid_t();
-    int kill(bool quiet = false);
+    int kill();
     int wait();
 
     void setSeparatePG(bool separatePG);