diff --git a/implementations/onblocks/BlobOnBlocks.cpp b/implementations/onblocks/BlobOnBlocks.cpp
index b850b456..737fa45a 100644
--- a/implementations/onblocks/BlobOnBlocks.cpp
+++ b/implementations/onblocks/BlobOnBlocks.cpp
@@ -4,6 +4,7 @@
 #include "datanodestore/DataLeafNode.h"
 #include "utils/Math.h"
 #include <cmath>
+#include <messmer/cpp-utils/assert/assert.h>
 
 using std::function;
 using cpputils::unique_ref;
@@ -49,9 +50,9 @@ void BlobOnBlocks::traverseLeaves(uint64_t beginByte, uint64_t sizeBytes, functi
 }
 
 void BlobOnBlocks::read(void *target, uint64_t offset, uint64_t count) const {
-  assert(offset <= _datatree->numStoredBytes() && offset + count <= size());
+  ASSERT(offset <= _datatree->numStoredBytes() && offset + count <= size(), "BlobOnBlocks::read() read outside blob. Use BlobOnBlocks::tryRead() if this should be allowed.");
   uint64_t read = tryRead(target, offset, count);
-  assert(read == count);
+  ASSERT(read == count, "BlobOnBlocks::read() couldn't read all requested bytes. Use BlobOnBlocks::tryRead() if this should be allowed.");
 }
 
 uint64_t BlobOnBlocks::tryRead(void *target, uint64_t offset, uint64_t count) const {
diff --git a/implementations/onblocks/BlobStoreOnBlocks.cpp b/implementations/onblocks/BlobStoreOnBlocks.cpp
index 86b3131a..795c6e5f 100644
--- a/implementations/onblocks/BlobStoreOnBlocks.cpp
+++ b/implementations/onblocks/BlobStoreOnBlocks.cpp
@@ -8,6 +8,7 @@
 #include "BlobStoreOnBlocks.h"
 #include "BlobOnBlocks.h"
 #include <messmer/cpp-utils/pointer/cast.h>
+#include <messmer/cpp-utils/assert/assert.h>
 
 using cpputils::unique_ref;
 using cpputils::make_unique_ref;
@@ -47,7 +48,7 @@ optional<unique_ref<Blob>> BlobStoreOnBlocks::load(const Key &key) {
 
 void BlobStoreOnBlocks::remove(unique_ref<Blob> blob) {
   auto _blob = dynamic_pointer_move<BlobOnBlocks>(blob);
-  assert(_blob != none);
+  ASSERT(_blob != none, "Passed Blob in BlobStoreOnBlocks::remove() is not a BlobOnBlocks.");
   _dataTreeStore->remove((*_blob)->releaseTree());
 }
 
diff --git a/implementations/onblocks/datanodestore/DataInnerNode.cpp b/implementations/onblocks/datanodestore/DataInnerNode.cpp
index fcfd9b6a..c2004912 100644
--- a/implementations/onblocks/datanodestore/DataInnerNode.cpp
+++ b/implementations/onblocks/datanodestore/DataInnerNode.cpp
@@ -1,5 +1,6 @@
 #include "DataInnerNode.h"
 #include "DataNodeStore.h"
+#include <messmer/cpp-utils/assert/assert.h>
 
 using blockstore::Block;
 using cpputils::Data;
@@ -13,7 +14,7 @@ namespace datanodestore {
 
 DataInnerNode::DataInnerNode(DataNodeView view)
 : DataNode(std::move(view)) {
-  assert(depth() > 0);
+  ASSERT(depth() > 0, "Inner node can't have depth 0. Is this a leaf maybe?");
 }
 
 DataInnerNode::~DataInnerNode() {
@@ -61,19 +62,19 @@ DataInnerNode::ChildEntry *DataInnerNode::getChild(unsigned int index) {
 }
 
 const DataInnerNode::ChildEntry *DataInnerNode::getChild(unsigned int index) const {
-  assert(index < numChildren());
+  ASSERT(index < numChildren(), "Accessing child out of range");
   return ChildrenBegin()+index;
 }
 
 void DataInnerNode::addChild(const DataNode &child) {
-  assert(numChildren() < maxStoreableChildren());
-  assert(child.depth() == depth()-1);
+  ASSERT(numChildren() < maxStoreableChildren(), "Adding more children than we can store");
+  ASSERT(child.depth() == depth()-1, "The child that should be added has wrong depth");
   node().setSize(node().Size()+1);
   LastChild()->setKey(child.key());
 }
 
 void DataInnerNode::removeLastChild() {
-  assert(node().Size() > 1);
+  ASSERT(node().Size() > 1, "There is no child to remove");
   node().setSize(node().Size()-1);
 }
 
diff --git a/implementations/onblocks/datanodestore/DataLeafNode.cpp b/implementations/onblocks/datanodestore/DataLeafNode.cpp
index 3ab7e910..2791c9af 100644
--- a/implementations/onblocks/datanodestore/DataLeafNode.cpp
+++ b/implementations/onblocks/datanodestore/DataLeafNode.cpp
@@ -1,5 +1,6 @@
 #include "DataLeafNode.h"
 #include "DataInnerNode.h"
+#include <messmer/cpp-utils/assert/assert.h>
 
 using blockstore::Block;
 using cpputils::Data;
@@ -13,8 +14,8 @@ namespace datanodestore {
 
 DataLeafNode::DataLeafNode(DataNodeView view)
 : DataNode(std::move(view)) {
-  assert(node().Depth() == 0);
-  assert(numBytes() <= maxStoreableBytes());
+  ASSERT(node().Depth() == 0, "Leaf node must have depth 0. Is it an inner node instead?");
+  ASSERT(numBytes() <= maxStoreableBytes(), "Leaf says it stores more bytes than it has space for");
 }
 
 DataLeafNode::~DataLeafNode() {
@@ -29,12 +30,12 @@ unique_ref<DataLeafNode> DataLeafNode::InitializeNewNode(unique_ref<Block> block
 }
 
 void DataLeafNode::read(void *target, uint64_t offset, uint64_t size) const {
-  assert(offset <= node().Size() && offset + size <= node().Size()); // Also check offset, because the addition could lead to overflows
+  ASSERT(offset <= node().Size() && offset + size <= node().Size(), "Read out of valid area"); // Also check offset, because the addition could lead to overflows
   std::memcpy(target, (uint8_t*)node().data() + offset, size);
 }
 
 void DataLeafNode::write(const void *source, uint64_t offset, uint64_t size) {
-  assert(offset <= node().Size() && offset + size <= node().Size()); // Also check offset, because the addition could lead to overflows
+  ASSERT(offset <= node().Size() && offset + size <= node().Size(), "Write out of valid area"); // Also check offset, because the addition could lead to overflows
   node().write(source, offset, size);
 }
 
@@ -43,7 +44,7 @@ uint32_t DataLeafNode::numBytes() const {
 }
 
 void DataLeafNode::resize(uint32_t new_size) {
-  assert(new_size <= maxStoreableBytes());
+  ASSERT(new_size <= maxStoreableBytes(), "Trying to resize to a size larger than the maximal size");
   uint32_t old_size = node().Size();
   if (new_size < old_size) {
     fillDataWithZeroesFromTo(new_size, old_size);
diff --git a/implementations/onblocks/datanodestore/DataNodeStore.cpp b/implementations/onblocks/datanodestore/DataNodeStore.cpp
index c44b4518..b70e8081 100644
--- a/implementations/onblocks/datanodestore/DataNodeStore.cpp
+++ b/implementations/onblocks/datanodestore/DataNodeStore.cpp
@@ -4,7 +4,7 @@
 #include "messmer/blockstore/interface/BlockStore.h"
 #include "messmer/blockstore/interface/Block.h"
 #include "messmer/blockstore/utils/BlockStoreUtils.h"
-
+#include <messmer/cpp-utils/assert/assert.h>
 
 using blockstore::BlockStore;
 using blockstore::Block;
@@ -28,7 +28,7 @@ DataNodeStore::~DataNodeStore() {
 }
 
 unique_ref<DataNode> DataNodeStore::load(unique_ref<Block> block) {
-  assert(block->size() == _layout.blocksizeBytes());
+  ASSERT(block->size() == _layout.blocksizeBytes(), "Loading block of wrong size");
   DataNodeView node(std::move(block));
 
   if (node.Depth() == 0) {
@@ -41,7 +41,7 @@ unique_ref<DataNode> DataNodeStore::load(unique_ref<Block> block) {
 }
 
 unique_ref<DataInnerNode> DataNodeStore::createNewInnerNode(const DataNode &first_child) {
-  assert(first_child.node().layout().blocksizeBytes() == _layout.blocksizeBytes());  // This might be violated if source is from a different DataNodeStore
+  ASSERT(first_child.node().layout().blocksizeBytes() == _layout.blocksizeBytes(), "Source node has wrong layout. Is it from the same DataNodeStore?");
   //TODO Initialize block and then create it in the blockstore - this is more efficient than creating it and then writing to it
   auto block = _blockstore->create(Data(_layout.blocksizeBytes()).FillWithZeroes());
   return DataInnerNode::InitializeNewNode(std::move(block), first_child);
@@ -63,14 +63,14 @@ optional<unique_ref<DataNode>> DataNodeStore::load(const Key &key) {
 }
 
 unique_ref<DataNode> DataNodeStore::createNewNodeAsCopyFrom(const DataNode &source) {
-  assert(source.node().layout().blocksizeBytes() == _layout.blocksizeBytes());  // This might be violated if source is from a different DataNodeStore
+  ASSERT(source.node().layout().blocksizeBytes() == _layout.blocksizeBytes(), "Source node has wrong layout. Is it from the same DataNodeStore?");
   auto newBlock = blockstore::utils::copyToNewBlock(_blockstore.get(), source.node().block());
   return load(std::move(newBlock));
 }
 
 unique_ref<DataNode> DataNodeStore::overwriteNodeWith(unique_ref<DataNode> target, const DataNode &source) {
-  assert(target->node().layout().blocksizeBytes() == _layout.blocksizeBytes());
-  assert(source.node().layout().blocksizeBytes() == _layout.blocksizeBytes());
+  ASSERT(target->node().layout().blocksizeBytes() == _layout.blocksizeBytes(), "Target node has wrong layout. Is it from the same DataNodeStore?");
+  ASSERT(source.node().layout().blocksizeBytes() == _layout.blocksizeBytes(), "Source node has wrong layout. Is it from the same DataNodeStore?");
   Key key = target->key();
   {
     auto targetBlock = target->node().releaseBlock();
@@ -78,7 +78,7 @@ unique_ref<DataNode> DataNodeStore::overwriteNodeWith(unique_ref<DataNode> targe
     blockstore::utils::copyTo(targetBlock.get(), source.node().block());
   }
   auto loaded = load(key);
-  assert(loaded != none);
+  ASSERT(loaded != none, "Couldn't load the target node after overwriting it");
   return std::move(*loaded);
 }
 
@@ -97,7 +97,7 @@ void DataNodeStore::removeSubtree(unique_ref<DataNode> node) {
   if (inner != nullptr) {
     for (uint32_t i = 0; i < inner->numChildren(); ++i) {
       auto child = load(inner->getChild(i)->key());
-      assert(child != none);
+      ASSERT(child != none, "Couldn't load child node");
       removeSubtree(std::move(*child));
     }
   }
diff --git a/implementations/onblocks/datatreestore/DataTree.cpp b/implementations/onblocks/datatreestore/DataTree.cpp
index a8e10312..90df408c 100644
--- a/implementations/onblocks/datatreestore/DataTree.cpp
+++ b/implementations/onblocks/datatreestore/DataTree.cpp
@@ -10,6 +10,7 @@
 #include "messmer/cpp-utils/pointer/cast.h"
 #include "messmer/cpp-utils/pointer/optional_ownership_ptr.h"
 #include <cmath>
+#include <messmer/cpp-utils/assert/assert.h>
 
 using blockstore::Key;
 using blobstore::onblocks::datanodestore::DataNodeStore;
@@ -45,7 +46,7 @@ DataTree::~DataTree() {
 
 void DataTree::removeLastDataLeaf() {
   auto deletePosOrNull = algorithms::GetLowestRightBorderNodeWithMoreThanOneChildOrNull(_nodeStore, _rootNode.get());
-  assert(deletePosOrNull.get() != nullptr); //TODO Correct exception (tree has only one leaf, can't shrink it)
+  ASSERT(deletePosOrNull.get() != nullptr, "Tree has only one leaf, can't shrink it.");
 
   deleteLastChildSubtree(deletePosOrNull.get());
 
@@ -54,10 +55,10 @@ void DataTree::removeLastDataLeaf() {
 
 void DataTree::ifRootHasOnlyOneChildReplaceRootWithItsChild() {
   DataInnerNode *rootNode = dynamic_cast<DataInnerNode*>(_rootNode.get());
-  assert(rootNode != nullptr);
+  ASSERT(rootNode != nullptr, "RootNode is not an inner node");
   if (rootNode->numChildren() == 1) {
     auto child = _nodeStore->load(rootNode->getChild(0)->key());
-    assert(child != none);
+    ASSERT(child != none, "Couldn't load first child of root node");
     _rootNode = _nodeStore->overwriteNodeWith(std::move(_rootNode), **child);
     _nodeStore->remove(std::move(*child));
   }
@@ -65,7 +66,7 @@ void DataTree::ifRootHasOnlyOneChildReplaceRootWithItsChild() {
 
 void DataTree::deleteLastChildSubtree(DataInnerNode *node) {
   auto lastChild = _nodeStore->load(node->LastChild()->key());
-  assert(lastChild != none);
+  ASSERT(lastChild != none, "Couldn't load last child");
   _nodeStore->removeSubtree(std::move(*lastChild));
   node->removeLastChild();
 }
@@ -105,7 +106,7 @@ unique_ref<DataNode> DataTree::createChainOfInnerNodes(unsigned int num, unique_
 }
 
 DataInnerNode* DataTree::increaseTreeDepth(unsigned int levels) {
-  assert(levels >= 1);
+  ASSERT(levels >= 1, "Parameter out of bounds: tried to increase tree depth by zero.");
   auto copyOfOldRoot = _nodeStore->createNewNodeAsCopyFrom(*_rootNode);
   auto chain = createChainOfInnerNodes(levels-1, copyOfOldRoot.get());
   auto newRootNode = DataNode::convertToNewInnerNode(std::move(_rootNode), *chain);
@@ -146,7 +147,7 @@ uint32_t DataTree::_numLeaves(const DataNode &node) const {
   const DataInnerNode &inner = dynamic_cast<const DataInnerNode&>(node);
   uint64_t numLeavesInLeftChildren = (inner.numChildren()-1) * leavesPerFullChild(inner);
   auto lastChild = _nodeStore->load(inner.LastChild()->key());
-  assert(lastChild != none);
+  ASSERT(lastChild != none, "Couldn't load last child");
   uint64_t numLeavesInRightChild = _numLeaves(**lastChild);
 
   return numLeavesInLeftChildren + numLeavesInRightChild;
@@ -154,7 +155,7 @@ uint32_t DataTree::_numLeaves(const DataNode &node) const {
 
 void DataTree::traverseLeaves(uint32_t beginIndex, uint32_t endIndex, function<void (DataLeafNode*, uint32_t)> func) {
   unique_lock<shared_mutex> lock(_mutex); //TODO Only lock when resizing
-  assert(beginIndex <= endIndex);
+  ASSERT(beginIndex <= endIndex, "Invalid parameters");
 
   uint8_t neededTreeDepth = utils::ceilLog(_nodeStore->layout().maxChildrenPerInnerNode(), endIndex);
   uint32_t numLeaves = this->numLeaves();
@@ -192,7 +193,7 @@ void DataTree::traverseLeaves(uint32_t beginIndex, uint32_t endIndex, function<v
 void DataTree::_traverseLeaves(DataNode *root, uint32_t leafOffset, uint32_t beginIndex, uint32_t endIndex, function<void (DataLeafNode*, uint32_t)> func) {
   DataLeafNode *leaf = dynamic_cast<DataLeafNode*>(root);
   if (leaf != nullptr) {
-    assert(beginIndex <= 1 && endIndex <= 1);
+    ASSERT(beginIndex <= 1 && endIndex <= 1, "If root node is a leaf, the (sub)tree has only one leaf - access indices must be 0 or 1.");
     if (beginIndex == 0 && endIndex == 1) {
       func(leaf, leafOffset);
     }
@@ -219,13 +220,13 @@ vector<unique_ref<DataNode>> DataTree::getOrCreateChildren(DataInnerNode *node,
   children.reserve(end-begin);
   for (uint32_t childIndex = begin; childIndex < std::min(node->numChildren(), end); ++childIndex) {
     auto child = _nodeStore->load(node->getChild(childIndex)->key());
-    assert(child != none);
+    ASSERT(child != none, "Couldn't load child node");
     children.emplace_back(std::move(*child));
   }
   for (uint32_t childIndex = node->numChildren(); childIndex < end; ++childIndex) {
     children.emplace_back(addChildTo(node));
   }
-  assert(children.size() == end-begin);
+  ASSERT(children.size() == end-begin, "Number of children in the result is wrong");
   return children;
 }
 
@@ -259,7 +260,7 @@ uint64_t DataTree::_numStoredBytes(const DataNode &root) const {
   const DataInnerNode &inner = dynamic_cast<const DataInnerNode&>(root);
   uint64_t numBytesInLeftChildren = (inner.numChildren()-1) * leavesPerFullChild(inner) * _nodeStore->layout().maxBytesPerLeaf();
   auto lastChild = _nodeStore->load(inner.LastChild()->key());
-  assert(lastChild != none);
+  ASSERT(lastChild != none, "Couldn't load last child");
   uint64_t numBytesInRightChild = _numStoredBytes(**lastChild);
 
   return numBytesInLeftChildren + numBytesInRightChild;
@@ -272,7 +273,7 @@ void DataTree::resizeNumBytes(uint64_t newNumBytes) {
     //TODO Faster implementation possible (no addDataLeaf()/removeLastDataLeaf() in a loop, but directly resizing)
     LastLeaf(_rootNode.get())->resize(_nodeStore->layout().maxBytesPerLeaf());
     uint64_t currentNumBytes = _numStoredBytes();
-    assert(currentNumBytes % _nodeStore->layout().maxBytesPerLeaf() == 0);
+    ASSERT(currentNumBytes % _nodeStore->layout().maxBytesPerLeaf() == 0, "The last leaf is not a max data leaf, although we just resized it to be one.");
     uint32_t currentNumLeaves = currentNumBytes / _nodeStore->layout().maxBytesPerLeaf();
     uint32_t newNumLeaves = std::max(1u, utils::ceilDivision(newNumBytes, _nodeStore->layout().maxBytesPerLeaf()));
 
@@ -285,7 +286,7 @@ void DataTree::resizeNumBytes(uint64_t newNumBytes) {
     uint32_t newLastLeafSize = newNumBytes - (newNumLeaves-1)*_nodeStore->layout().maxBytesPerLeaf();
     LastLeaf(_rootNode.get())->resize(newLastLeafSize);
   }
-  assert(newNumBytes == numStoredBytes());
+  ASSERT(newNumBytes == numStoredBytes(), "We resized to the wrong number of bytes");
 }
 
 optional_ownership_ptr<DataLeafNode> DataTree::LastLeaf(DataNode *root) {
@@ -296,7 +297,7 @@ optional_ownership_ptr<DataLeafNode> DataTree::LastLeaf(DataNode *root) {
 
   DataInnerNode *inner = dynamic_cast<DataInnerNode*>(root);
   auto lastChild = _nodeStore->load(inner->LastChild()->key());
-  assert(lastChild != none);
+  ASSERT(lastChild != none, "Couldn't load last child");
   return WithOwnership(LastLeaf(std::move(*lastChild)));
 }
 
@@ -306,9 +307,9 @@ unique_ref<DataLeafNode> DataTree::LastLeaf(unique_ref<DataNode> root) {
     return std::move(*leaf);
   }
   auto inner = dynamic_pointer_move<DataInnerNode>(root);
-  assert(inner != none);
+  ASSERT(inner != none, "Root node is neither a leaf nor an inner node");
   auto child = _nodeStore->load((*inner)->LastChild()->key());
-  assert(child != none);
+  ASSERT(child != none, "Couldn't load last child");
   return LastLeaf(std::move(*child));
 }
 
diff --git a/implementations/onblocks/datatreestore/impl/algorithms.cpp b/implementations/onblocks/datatreestore/impl/algorithms.cpp
index 3d2d71c2..89d64903 100644
--- a/implementations/onblocks/datatreestore/impl/algorithms.cpp
+++ b/implementations/onblocks/datatreestore/impl/algorithms.cpp
@@ -4,6 +4,7 @@
 
 #include "../../datanodestore/DataInnerNode.h"
 #include "../../datanodestore/DataNodeStore.h"
+#include <messmer/cpp-utils/assert/assert.h>
 
 using std::function;
 using cpputils::optional_ownership_ptr;
@@ -24,7 +25,7 @@ namespace algorithms {
 optional<unique_ref<DataInnerNode>> getLastChildAsInnerNode(DataNodeStore *nodeStore, const DataInnerNode &node) {
   Key key = node.LastChild()->key();
   auto lastChild = nodeStore->load(key);
-  assert(lastChild != none);
+  ASSERT(lastChild != none, "Couldn't load last child");
   return dynamic_pointer_move<DataInnerNode>(*lastChild);
 }
 
@@ -39,7 +40,7 @@ optional_ownership_ptr<DataInnerNode> GetLowestInnerRightBorderNodeWithCondition
     if (condition(*currentNode)) {
       result = std::move(currentNode);
     }
-    assert(lastChild != none || static_cast<int>(i) == rootNode->depth()-1);
+    ASSERT(lastChild != none || static_cast<int>(i) == rootNode->depth()-1, "Couldn't get last child as inner node but we're not deep enough yet for the last child to be a leaf");
     if (lastChild != none) {
       currentNode = cpputils::WithOwnership(std::move(*lastChild));
     }
diff --git a/test/implementations/onblocks/datatreestore/testutils/DataTreeTest.cpp b/test/implementations/onblocks/datatreestore/testutils/DataTreeTest.cpp
index e8864222..d906dff0 100644
--- a/test/implementations/onblocks/datatreestore/testutils/DataTreeTest.cpp
+++ b/test/implementations/onblocks/datatreestore/testutils/DataTreeTest.cpp
@@ -41,7 +41,7 @@ unique_ref<DataInnerNode> DataTreeTest::CreateInner(initializer_list<const DataN
 }
 
 unique_ref<DataInnerNode> DataTreeTest::CreateInner(vector<const DataNode*> children) {
-  assert(children.size() >= 1);
+  ASSERT(children.size() >= 1, "An inner node must have at least one child");
   auto node = nodeStore->createNewInnerNode(**children.begin());
   for(auto child = children.begin()+1; child != children.end(); ++child) {
     node->addChild(**child);
diff --git a/test/implementations/onblocks/datatreestore/testutils/TwoLevelDataFixture.h b/test/implementations/onblocks/datatreestore/testutils/TwoLevelDataFixture.h
index 03b4748e..6e2e8594 100644
--- a/test/implementations/onblocks/datatreestore/testutils/TwoLevelDataFixture.h
+++ b/test/implementations/onblocks/datatreestore/testutils/TwoLevelDataFixture.h
@@ -5,6 +5,7 @@
 #include <messmer/cpp-utils/macros.h>
 #include <messmer/cpp-utils/pointer/cast.h>
 #include "LeafDataFixture.h"
+#include <messmer/cpp-utils/assert/assert.h>
 
 //TODO Rename, since we now allow any number of levels
 // A data fixture containing data for a two-level tree (one inner node with leaf children).
@@ -70,7 +71,8 @@ private:
     case SizePolicy::Unchanged:
       return leaf->numBytes();
     default:
-      assert(false);
+      ASSERT(false, "Unknown size policy");
+      abort(); // The assert above already aborts. This is just to prevent the style checker from complaining about exiting a non-void function
     }
   }