diff --git a/crates/proof-of-sql/src/base/database/expression_evaluation.rs b/crates/proof-of-sql/src/base/database/expression_evaluation.rs
index 9b4da0b90..5400fa805 100644
--- a/crates/proof-of-sql/src/base/database/expression_evaluation.rs
+++ b/crates/proof-of-sql/src/base/database/expression_evaluation.rs
@@ -9,9 +9,10 @@ use crate::base::{
 };
 use alloc::{format, string::ToString, vec};
 use proof_of_sql_parser::{
-    intermediate_ast::{BinaryOperator, Expression, Literal, UnaryOperator},
+    intermediate_ast::{BinaryOperator, Expression, Literal},
     Identifier,
 };
+use sqlparser::ast::UnaryOperator;
 
 impl<S: Scalar> OwnedTable<S> {
     /// Evaluate an expression on the table.
@@ -20,7 +21,7 @@ impl<S: Scalar> OwnedTable<S> {
             Expression::Column(identifier) => self.evaluate_column(identifier),
             Expression::Literal(lit) => self.evaluate_literal(lit),
             Expression::Binary { op, left, right } => self.evaluate_binary_expr(*op, left, right),
-            Expression::Unary { op, expr } => self.evaluate_unary_expr(*op, expr),
+            Expression::Unary { op, expr } => self.evaluate_unary_expr((*op).into(), expr),
             _ => Err(ExpressionEvaluationError::Unsupported {
                 expression: format!("Expression {expr:?} is not supported yet"),
             }),
@@ -74,6 +75,10 @@ impl<S: Scalar> OwnedTable<S> {
         let column = self.evaluate(expr)?;
         match op {
             UnaryOperator::Not => Ok(column.element_wise_not()?),
+            // Handle unsupported unary operators
+            _ => Err(ExpressionEvaluationError::Unsupported {
+                expression: format!("Unary operator '{op}' is not supported."),
+            }),
         }
     }
 
diff --git a/crates/proof-of-sql/src/sql/parse/dyn_proof_expr_builder.rs b/crates/proof-of-sql/src/sql/parse/dyn_proof_expr_builder.rs
index 50550f8c2..a50a271d0 100644
--- a/crates/proof-of-sql/src/sql/parse/dyn_proof_expr_builder.rs
+++ b/crates/proof-of-sql/src/sql/parse/dyn_proof_expr_builder.rs
@@ -19,10 +19,11 @@ use crate::{
 };
 use alloc::{borrow::ToOwned, boxed::Box, format, string::ToString};
 use proof_of_sql_parser::{
-    intermediate_ast::{AggregationOperator, BinaryOperator, Expression, Literal, UnaryOperator},
+    intermediate_ast::{AggregationOperator, BinaryOperator, Expression, Literal},
     posql_time::{PoSQLTimeUnit, PoSQLTimestampError},
     Identifier,
 };
+use sqlparser::ast::UnaryOperator;
 
 /// Builder that enables building a `proofs::sql::proof_exprs::DynProofExpr` from
 /// a `proof_of_sql_parser::intermediate_ast::Expression`.
@@ -60,7 +61,7 @@ impl DynProofExprBuilder<'_> {
             Expression::Column(identifier) => self.visit_column(*identifier),
             Expression::Literal(lit) => self.visit_literal(lit),
             Expression::Binary { op, left, right } => self.visit_binary_expr(*op, left, right),
-            Expression::Unary { op, expr } => self.visit_unary_expr(*op, expr),
+            Expression::Unary { op, expr } => self.visit_unary_expr((*op).into(), expr),
             Expression::Aggregation { op, expr } => self.visit_aggregate_expr(*op, expr),
             _ => Err(ConversionError::Unprovable {
                 error: format!("Expression {expr:?} is not supported yet"),
@@ -136,6 +137,10 @@ impl DynProofExprBuilder<'_> {
         let expr = self.visit_expr(expr);
         match op {
             UnaryOperator::Not => DynProofExpr::try_new_not(expr?),
+            // Handle unsupported operators
+            _ => Err(ConversionError::UnsupportedOperation {
+                message: format!("{op:?}"),
+            }),
         }
     }
 
diff --git a/crates/proof-of-sql/src/sql/parse/error.rs b/crates/proof-of-sql/src/sql/parse/error.rs
index c608093dc..908749c2d 100644
--- a/crates/proof-of-sql/src/sql/parse/error.rs
+++ b/crates/proof-of-sql/src/sql/parse/error.rs
@@ -139,6 +139,13 @@ pub enum ConversionError {
         /// The underlying error
         error: String,
     },
+
+    #[snafu(display("Unsupported operator: {message}"))]
+    /// Unsupported operation
+    UnsupportedOperation {
+        /// The operator that is unsupported
+        message: String,
+    },
 }
 
 impl From<String> for ConversionError {
diff --git a/crates/proof-of-sql/src/sql/parse/query_context_builder.rs b/crates/proof-of-sql/src/sql/parse/query_context_builder.rs
index dda1f6101..8e9bd3309 100644
--- a/crates/proof-of-sql/src/sql/parse/query_context_builder.rs
+++ b/crates/proof-of-sql/src/sql/parse/query_context_builder.rs
@@ -9,15 +9,15 @@ use crate::base::{
         BigDecimalExt,
     },
 };
-use alloc::{boxed::Box, string::ToString, vec::Vec};
+use alloc::{boxed::Box, format, string::ToString, vec::Vec};
 use proof_of_sql_parser::{
     intermediate_ast::{
         AggregationOperator, AliasedResultExpr, BinaryOperator, Expression, Literal, OrderBy,
-        SelectResultExpr, Slice, TableExpression, UnaryOperator,
+        SelectResultExpr, Slice, TableExpression,
     },
     Identifier, ResourceId,
 };
-
+use sqlparser::ast::UnaryOperator;
 pub struct QueryContextBuilder<'a> {
     context: QueryContext,
     schema_accessor: &'a dyn SchemaAccessor,
@@ -137,7 +137,7 @@ impl<'a> QueryContextBuilder<'a> {
             Expression::Wildcard => Ok(ColumnType::BigInt), // Since COUNT(*) = COUNT(1)
             Expression::Literal(literal) => self.visit_literal(literal),
             Expression::Column(_) => self.visit_column_expr(expr),
-            Expression::Unary { op, expr } => self.visit_unary_expr(*op, expr),
+            Expression::Unary { op, expr } => self.visit_unary_expr((*op).into(), expr),
             Expression::Binary { op, left, right } => self.visit_binary_expr(*op, left, right),
             Expression::Aggregation { op, expr } => self.visit_agg_expr(*op, expr),
         }
@@ -192,6 +192,10 @@ impl<'a> QueryContextBuilder<'a> {
                 }
                 Ok(ColumnType::Boolean)
             }
+            // Handle unsupported operators
+            _ => Err(ConversionError::UnsupportedOperation {
+                message: format!("{op:?}"),
+            }),
         }
     }