diff --git a/CMakeLists.txt b/CMakeLists.txt
index 360f4e86..df28a3bd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,11 +29,14 @@ include_directories(${PROJECT_SOURCE_DIR} "${PROJECT_SOURCE_DIR}/dns")
 set_source_files_properties(dns/dns.c PROPERTIES COMPILE_FLAGS -std=c99)
 add_library(dill ${sources})
 
+find_package(Threads REQUIRED)
+target_link_libraries(dill PUBLIC Threads::Threads)
+
 # check and enable rt if available
 list(APPEND CMAKE_REQUIRED_LIBRARIES rt)
 check_symbol_exists(clock_gettime time.h HAVE_CLOCK_GETTIME)
 if(HAVE_CLOCK_GETTIME)
-  target_link_libraries(dill rt)
+  target_link_libraries(dill PUBLIC rt)
 endif()
 
 # Installation (https://github.com/forexample/package-example)
@@ -118,12 +121,12 @@ set(CMAKE_REQUIRED_DEFINITIONS )
 
 check_function_exists(mprotect HAVE_MPROTECT)
 if(HAVE_MPROTECT)
-  add_definitions(-DHAVE_MPROTECT)
+  target_compile_definitions(dill PUBLIC HAVE_MPROTECT)
 endif()
 
 check_function_exists(posix_memalign HAVE_POSIX_MEMALIGN)
 if(HAVE_POSIX_MEMALIGN)
-  add_definitions(-DHAVE_POSIX_MEMALIGN)
+  target_compile_definitions(dill PUBLIC HAVE_POSIX_MEMALIGN)
 endif()
 
 # tests
diff --git a/perf/chan.c b/perf/chan.c
index 2e0bca17..e9ed24e6 100644
--- a/perf/chan.c
+++ b/perf/chan.c
@@ -65,8 +65,10 @@ int main(int argc, char *argv[]) {
     printf("done %ldM roundtrips in %f seconds\n",
         (long)(count / 1000000), ((float)duration) / 1000);
     printf("duration of passing a single message: %ld ns\n", ns);
-    printf("message passes per second: %fM\n",
-        (float)(1000000000 / ns) / 1000000);
+    if (ns > 0) {
+      printf("message passes per second: %fM\n",
+          (float)(1000000000 / ns) / 1000000);
+    }
 
     return 0;
 }
diff --git a/perf/choose.c b/perf/choose.c
index 38940bfc..6900fe77 100644
--- a/perf/choose.c
+++ b/perf/choose.c
@@ -67,8 +67,10 @@ int main(int argc, char *argv[]) {
     printf("done %ldM roundtrips in %f seconds\n",
         (long)(count / 1000000), ((float)duration) / 1000);
     printf("duration of passing a single message: %ld ns\n", ns);
-    printf("message passes per second: %fM\n",
+    if (ns > 0) {
+      printf("message passes per second: %fM\n",
         (float)(1000000000 / ns) / 1000000);
+    }
 
     return 0;
 }
diff --git a/perf/ctxswitch.c b/perf/ctxswitch.c
index 9a2504d1..700f457a 100644
--- a/perf/ctxswitch.c
+++ b/perf/ctxswitch.c
@@ -57,8 +57,10 @@ int main(int argc, char *argv[]) {
     printf("performed %ldM context switches in %f seconds\n",
         (long)(count * 2 / 1000000), ((float)duration) / 1000);
     printf("duration of one context switch: %ld ns\n", ns);
-    printf("context switches per second: %fM\n",
+    if (ns > 0) {
+      printf("context switches per second: %fM\n",
         (float)(1000000000 / ns) / 1000000);
+    }
 
     return 0;
 }
diff --git a/perf/go.c b/perf/go.c
index f1c8f13e..a45b2d77 100644
--- a/perf/go.c
+++ b/perf/go.c
@@ -55,8 +55,10 @@ int main(int argc, char *argv[]) {
     printf("executed %ldM coroutines in %f seconds\n",
         (long)(count / 1000000), ((float)duration) / 1000);
     printf("duration of one coroutine creation+termination: %ld ns\n", ns);
-    printf("coroutine creations+terminations per second: %fM\n",
-        (float)(1000000000 / ns) / 1000000);
+    if (ns > 0) {
+      printf("coroutine creations+terminations per second: %fM\n",
+          (float)(1000000000 / ns) / 1000000);
+    }
 
     return 0;
 }
diff --git a/perf/hdone.c b/perf/hdone.c
index 1afe001a..414c79ae 100644
--- a/perf/hdone.c
+++ b/perf/hdone.c
@@ -65,8 +65,10 @@ int main(int argc, char *argv[]) {
     printf("done %ldM coroutine/channel cancellations in %f seconds\n",
         (long)(count / 1000000), ((float)duration) / 1000);
     printf("duration of coroutine/channel cancellation: %ld ns\n", ns);
-    printf("coroutine/channel cancellations per second: %fM\n",
-        (float)(1000000000 / ns) / 1000000);
+    if (ns > 0) {
+      printf("coroutine/channel cancellations per second: %fM\n",
+          (float)(1000000000 / ns) / 1000000);
+    }
 
     return 0;
 }
diff --git a/perf/whispers.c b/perf/whispers.c
index d1f3487e..e509ca07 100644
--- a/perf/whispers.c
+++ b/perf/whispers.c
@@ -68,8 +68,10 @@ int main(int argc, char *argv[]) {
     printf("took %f seconds\n", (float)duration / 1000);
     printf("performed %ld whispers in %f seconds\n", count, ((float)duration) / 1000);
     printf("duration of one whisper: %ld ns\n", ns);
-    printf("whispers per second: %fM\n",
+    if (ns > 0) {
+      printf("whispers per second: %fM\n",
         (float)(1000000000 / ns) / 1000000);
+    }
 
     return 0;
 }