diff --git a/src/fs.c b/src/fs.c
index 6c886dd..ed86000 100644
--- a/src/fs.c
+++ b/src/fs.c
@@ -1254,7 +1254,7 @@ int fs_truncate(void *d)
 
 		// look through base inode blocks
 		for (int i = 0; i < BLOCK_ADDRESSES_PER_INODE; i++, blocks_seen++) {
-			if ((blocks_seen > new_block_amount) && (f.blocks[i])) {
+			if ((blocks_seen >= new_block_amount) && (f.blocks[i])) {
 				mark_free(f.blocks[i]);
 				f.blocks[i] = 0;
 			}
@@ -1270,7 +1270,7 @@ int fs_truncate(void *d)
 			read_block(next_ext, (void *) &ext);
 
 			for (int i = 0; i < BLOCK_ADDRESSES_PER_INODE_EXTENSION; i++, blocks_seen++) {
-				if ((blocks_seen > new_block_amount) && (ext.blocks[i])) {
+				if ((blocks_seen >= new_block_amount) && (ext.blocks[i])) {
 					mark_free(ext.blocks[i]);
 					ext.blocks[i] = 0;
 				}
@@ -1281,7 +1281,11 @@ int fs_truncate(void *d)
 		}
 
 		// look through inode extensions themselves
-		int required_extensions = (f.size - BLOCK_ADDRESSES_PER_INODE) / BLOCK_ADDRESSES_PER_INODE_EXTENSION;
+		int required_blocks_after_base_inode = (int) f.size - (int) BLOCK_ADDRESSES_PER_INODE;
+		int required_extensions = required_blocks_after_base_inode >= 0
+			? required_blocks_after_base_inode / BLOCK_ADDRESSES_PER_INODE_EXTENSION
+			: 0;
+
 		if ((f.size - BLOCK_ADDRESSES_PER_INODE) % BLOCK_ADDRESSES_PER_INODE_EXTENSION)
 			required_extensions++;
 
@@ -1291,23 +1295,23 @@ int fs_truncate(void *d)
 			// zero base inode next_extension ptr
 			f.next_extension = 0;
 			write_block(read_inode_ptr(file_inode_ptr), (void *) &f);
+		} else {
+			// seek to last required extension
+			for (int i = 0; i < required_extensions; i++) {
+				if (!next_ext)
+					return 0;
+
+				curr_ext = next_ext;
+				read_block(curr_ext, (void *) &ext);
+				next_ext = ext.next_extension;
+			}
+
+			// remove next_extension ptr
+			ext.next_extension = 0;
+			write_block(curr_ext, (void *) &ext);
 		}
 
-		// seek to last required extension
-		for (int i = 0; i < required_extensions; i++) {
-			if (!next_ext)
-				return 0;
-
-			curr_ext = next_ext;
-			read_block(next_ext, (void *) &ext);
-			next_ext = ext.next_extension;
-		}
-
-		// remove next_extension ptr
-		ext.next_extension = 0;
-		write_block(curr_ext, (void *) &ext);
-
-		// erase all extensions after this one
+		// erase all remaining extensions
 		while (next_ext) {
 			mark_free(next_ext);
 			read_block(next_ext, (void *) &ext);