diff --git a/SConstruct b/SConstruct
index 0f202ef..b69d412 100644
--- a/SConstruct
+++ b/SConstruct
@@ -194,6 +194,7 @@ if env["BOOTDISK"] == "1":
     Depends(bootdisk, "#build/sbin/ifconfig/ifconfig")
     Depends(bootdisk, "#build/sbin/init/init")
     Depends(bootdisk, "#build/sys/castor")
+    Depends(bootdisk, "#build/tests/pthreadtest")
     Depends(bootdisk, "#build/tests/threadtest")
     env.Alias('bootdisk', '#build/bootdisk.img')
     env.Install('$PREFIX/','#build/bootdisk.img')
diff --git a/include/assert.h b/include/assert.h
index 8146eae..7ce90bb 100644
--- a/include/assert.h
+++ b/include/assert.h
@@ -4,14 +4,14 @@
 
 #ifndef NDEBUG
 
-#define assert(_expr)
+#define assert(_expr) \
+    if (!(_expr)) { \
+	__assert(__func__, __FILE__, __LINE__, #_expr); \
+    }
 
 #else
 
-#define assert(_expr) \
-    if (e) { \
-	__assert(__func__, __FILE__, __LINE__, #e); \
-    }
+#define assert(_expr)
 
 #endif
 
diff --git a/release/bootdisk.manifest b/release/bootdisk.manifest
index a8e687d..04d2346 100644
--- a/release/bootdisk.manifest
+++ b/release/bootdisk.manifest
@@ -14,6 +14,7 @@ DIR /
     FILE init build/sbin/init/init
   END
   DIR tests
+    FILE pthreadtest build/tests/pthreadtest
     FILE threadtest build/tests/threadtest
   END
   FILE LICENSE LICENSE
diff --git a/tests/SConscript b/tests/SConscript
index a73c457..ad064d4 100644
--- a/tests/SConscript
+++ b/tests/SConscript
@@ -10,4 +10,5 @@ test_env.Append(CPPPATH = ['#build/include'])
 test_env.Append(LIBPATH = ['#build/lib/libc'], LIBS = ['c'])
 
 test_env.Program("threadtest", ["threadtest.c"])
+test_env.Program("pthreadtest", ["pthreadtest.c"])
 
diff --git a/tests/pthreadtest.c b/tests/pthreadtest.c
new file mode 100644
index 0000000..fbca42c
--- /dev/null
+++ b/tests/pthreadtest.c
@@ -0,0 +1,48 @@
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <pthread.h>
+
+void *
+thread_simple(void *arg)
+{
+    printf("thread_simple %p!\n", arg);
+
+    return arg;
+}
+
+int
+main(int argc, const char *argv[])
+{
+    int status;
+    pthread_t thr;
+    void *result;
+
+    printf("PThread Test\n");
+
+    // Simple thread test
+    printf("simple test\n");
+    status = pthread_create(&thr, NULL, thread_simple, NULL);
+    printf("status %d\n", status);
+    assert(status == 0);
+    status = pthread_join(thr, &result);
+    printf("status %d\n", status);
+    assert(status == 0);
+    assert(result == NULL);
+
+    // Return value test
+    printf("return value test\n");
+    status = pthread_create(&thr, NULL, thread_simple, (void *)1);
+    assert(status == 0);
+    status = pthread_join(thr, &result);
+    assert(status == 0);
+    assert(result == (void *)1);
+
+    printf("Success!\n");
+
+    return 0;
+}
+