diff --git a/headers/private/kernel/condition_variable.h b/headers/private/kernel/condition_variable.h
index 1b733b910b..7943ca7fed 100644
--- a/headers/private/kernel/condition_variable.h
+++ b/headers/private/kernel/condition_variable.h
@@ -8,6 +8,8 @@
 
 #include <OS.h>
 
+#include <debug.h>
+
 #ifdef __cplusplus
 
 #include <util/OpenHashTable.h>
@@ -18,11 +20,28 @@ class PrivateConditionVariable;
 
 struct PrivateConditionVariableEntry {
 public:
+#if KDEBUG
+	inline PrivateConditionVariableEntry()
+		: fVariable(NULL)
+	{
+	}
+
+	inline ~PrivateConditionVariableEntry()
+	{
+		if (fVariable != NULL) {
+			panic("Destroying condition variable entry %p, but it's still "
+				"attached to variable %p\n", this, fVariable);
+		}
+	}
+#endif
+
 	inline	PrivateConditionVariable* Variable() const
 		{ return fVariable; }
 
 	inline	PrivateConditionVariableEntry* ThreadNext() const
 		{ return fThreadNext; }
+	inline	PrivateConditionVariableEntry* ThreadPrevious() const
+		{ return fThreadPrevious; }
 
 	class Private;
 
diff --git a/src/system/kernel/condition_variable.cpp b/src/system/kernel/condition_variable.cpp
index 43be0e2e95..3a5ab79fc0 100644
--- a/src/system/kernel/condition_variable.cpp
+++ b/src/system/kernel/condition_variable.cpp
@@ -107,6 +107,8 @@ PrivateConditionVariableEntry::Add(const void* object,
 	if (threadNext) {
 		fThreadPrevious = threadNext->fThreadPrevious;
 		threadNext->fThreadPrevious = this;
+		if (fThreadPrevious)
+			fThreadPrevious->fThreadNext = this;
 	} else
 		fThreadPrevious = NULL;
 
@@ -399,7 +401,7 @@ condition_variable_interrupt_thread(struct thread* thread)
 	// re-get the thread and do the checks again
 	thread = thread_get_thread_struct_locked(threadID);
 
-	if (thread != NULL || thread->state != B_THREAD_WAITING
+	if (thread == NULL || thread->state != B_THREAD_WAITING
 		|| thread->condition_variable_entry == NULL) {
 		return B_BAD_VALUE;
 	}
@@ -417,6 +419,7 @@ condition_variable_interrupt_thread(struct thread* thread)
 	PrivateConditionVariableEntry::Private(*entry).SetResult(B_INTERRUPTED);
 
 	// remove all of the thread's entries from their variables
+	ASSERT(entry->ThreadPrevious() == NULL);
 	while (entry) {
 		PrivateConditionVariableEntry::Private(*entry).Remove();
 		entry = entry->ThreadNext();