diff --git a/src/flow/binary/balancing.rs b/src/flow/binary/balancing.rs
index 96de525..ecdf3ed 100644
--- a/src/flow/binary/balancing.rs
+++ b/src/flow/binary/balancing.rs
@@ -48,11 +48,11 @@ pub enum BalancingError {
 impl Display for BalancingError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
-            Self::Height(height_error) => write!(f, "invalid height: {height_error}"),
+            Self::Height(height_error) => write!(f, "invalid height: {height_error}."),
             Self::Balance(hl, hr) => write!(f, "unbalanced node: {hl} {hr}."),
-            Self::HeightOverflow => write!(f, "tree height overflow"),
+            Self::HeightOverflow => write!(f, "tree height overflow."),
             Self::HeightMismatch { children, parent } => {
-                write!(f, "child-parent height mismatch: {children:?}, {parent}")
+                write!(f, "child-parent height mismatch: {children:?}, {parent}.")
             }
         }
     }