diff --git a/build/jam/ArchitectureRules b/build/jam/ArchitectureRules
index 9421ed89f8..602683b2c0 100644
--- a/build/jam/ArchitectureRules
+++ b/build/jam/ArchitectureRules
@@ -733,7 +733,7 @@ rule ArchitectureSetupWarnings architecture
 	EnableWerror src add-ons kernel file_systems nfs4 ;
 #	EnableWerror src add-ons kernel file_systems ntfs ;
 	EnableWerror src add-ons kernel file_systems packagefs ;
-#	EnableWerror src add-ons kernel file_systems ramfs ;
+	EnableWerror src add-ons kernel file_systems ramfs ;
 	EnableWerror src add-ons kernel file_systems reiserfs ;
 	EnableWerror src add-ons kernel file_systems udf ;
 	EnableWerror src add-ons kernel file_systems userlandfs ;
diff --git a/src/add-ons/kernel/file_systems/ramfs/Attribute.cpp b/src/add-ons/kernel/file_systems/ramfs/Attribute.cpp
index 2a1196c6b6..66bcbd7b2e 100644
--- a/src/add-ons/kernel/file_systems/ramfs/Attribute.cpp
+++ b/src/add-ons/kernel/file_systems/ramfs/Attribute.cpp
@@ -72,7 +72,7 @@ Attribute::WriteAt(off_t offset, const void *buffer, size_t size,
 {
 	// get the current key for the attribute
 	uint8 oldKey[kMaxIndexKeyLength];
-	size_t oldLength;
+	size_t oldLength = kMaxIndexKeyLength;
 	GetKey(oldKey, &oldLength);
 
 	// write the new value
@@ -80,12 +80,12 @@ Attribute::WriteAt(off_t offset, const void *buffer, size_t size,
 
 	// If there is an index and a change has been made within the key, notify
 	// the index.
-	if (offset < kMaxIndexKeyLength && size > 0 && fIndex)
+	if (offset < (off_t)kMaxIndexKeyLength && size > 0 && fIndex)
 		fIndex->Changed(this, oldKey, oldLength);
 
 	// update live queries
 	uint8 newKey[kMaxIndexKeyLength];
-	size_t newLength;
+	size_t newLength = kMaxIndexKeyLength;
 	GetKey(newKey, &newLength);
 	GetVolume()->UpdateLiveQueries(NULL, fNode, GetName(), fType, oldKey,
 		oldLength, newKey, newLength);
diff --git a/src/add-ons/kernel/file_systems/ramfs/AttributeIndexImpl.cpp b/src/add-ons/kernel/file_systems/ramfs/AttributeIndexImpl.cpp
index 8a77a6baec..35df934a7c 100644
--- a/src/add-ons/kernel/file_systems/ramfs/AttributeIndexImpl.cpp
+++ b/src/add-ons/kernel/file_systems/ramfs/AttributeIndexImpl.cpp
@@ -259,7 +259,7 @@ AttributeIndexImpl::Changed(Attribute *attribute, const uint8 *oldKey,
 			}
 		}
 		// re-insert the attribute
-		if (fKeyLength > 0 && attribute->GetSize() != fKeyLength) {
+		if (fKeyLength > 0 && attribute->GetSize() != (off_t)fKeyLength) {
 			attribute->SetIndex(this, false);
 		} else {
 			error = fAttributes->Insert(attribute);
diff --git a/src/add-ons/kernel/file_systems/ramfs/DataContainer.cpp b/src/add-ons/kernel/file_systems/ramfs/DataContainer.cpp
index 61f1107da1..bf224a1786 100644
--- a/src/add-ons/kernel/file_systems/ramfs/DataContainer.cpp
+++ b/src/add-ons/kernel/file_systems/ramfs/DataContainer.cpp
@@ -136,7 +136,7 @@ DataContainer::WriteAt(off_t offset, const void *_buffer, size_t size,
 		return error;
 
 	// resize the container, if necessary
-	if ((offset + size) > fSize)
+	if ((offset + (off_t)size) > fSize)
 		error = Resize(offset + size);
 	if (error != B_OK)
 		return error;